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2020-06-25netfilter: iptables: Split ipt_unregister_table() into pre_exit and exit ↵David Wilder
helpers. The pre_exit will un-register the underlying hook and .exit will do the table freeing. The netns core does an unconditional synchronize_rcu after the pre_exit hooks insuring no packets are in flight that have picked up the pointer before completing the un-register. Fixes: b9e69e127397 ("netfilter: xtables: don't hook tables by default") Signed-off-by: David Wilder <dwilder@us.ibm.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-06-25netfilter: Add MODULE_DESCRIPTION entries to kernel modulesRob Gill
The user tool modinfo is used to get information on kernel modules, including a description where it is available. This patch adds a brief MODULE_DESCRIPTION to netfilter kernel modules (descriptions taken from Kconfig file or code comments) Signed-off-by: Rob Gill <rrobgill@protonmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-06-25netfilter: ipset: fix unaligned atomic accessRussell King
When using ip_set with counters and comment, traffic causes the kernel to panic on 32-bit ARM: Alignment trap: not handling instruction e1b82f9f at [<bf01b0dc>] Unhandled fault: alignment exception (0x221) at 0xea08133c PC is at ip_set_match_extensions+0xe0/0x224 [ip_set] The problem occurs when we try to update the 64-bit counters - the faulting address above is not 64-bit aligned. The problem occurs due to the way elements are allocated, for example: set->dsize = ip_set_elem_len(set, tb, 0, 0); map = ip_set_alloc(sizeof(*map) + elements * set->dsize); If the element has a requirement for a member to be 64-bit aligned, and set->dsize is not a multiple of 8, but is a multiple of four, then every odd numbered elements will be misaligned - and hitting an atomic64_add() on that element will cause the kernel to panic. ip_set_elem_len() must return a size that is rounded to the maximum alignment of any extension field stored in the element. This change ensures that is the case. Fixes: 95ad1f4a9358 ("netfilter: ipset: Fix extension alignment") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-06-24drm/amd: fix potential memleak in err branchBernard Zhao
The function kobject_init_and_add alloc memory like: kobject_init_and_add->kobject_add_varg->kobject_set_name_vargs ->kvasprintf_const->kstrdup_const->kstrdup->kmalloc_track_caller ->kmalloc_slab, in err branch this memory not free. If use kmemleak, this path maybe catched. These changes are to add kobject_put in kobject_init_and_add failed branch, fix potential memleak. Signed-off-by: Bernard Zhao <bernard@vivo.com> Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com> Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2020-06-24drm/amd/display: Fix ineffective setting of max bpc propertyStylon Wang
[Why] Regression was introduced where setting max bpc property has no effect on the atomic check and final commit. It has the same effect as max bpc being stuck at 8. [How] Correctly propagate max bpc with the new connector state. Signed-off-by: Stylon Wang <stylon.wang@amd.com> Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com> Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2020-06-24drm/amd/display: Enable output_bpc property on all outputsStylon Wang
[Why] Connector property output_bpc is available on DP/eDP only. New IGT tests would benifit if this property works on HDMI. [How] Enable this read-only property on all types of connectors. Signed-off-by: Stylon Wang <stylon.wang@amd.com> Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com> Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2020-06-24drm/amdgpu: add fw release for sdma v5_0Wenhui Sheng
sdma fw isn't released when module exit Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com> Signed-off-by: Wenhui Sheng <Wenhui.Sheng@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org
2020-06-24qed: add missing error test for DBG_STATUS_NO_MATCHING_FRAMING_MODEColin Ian King
The error DBG_STATUS_NO_MATCHING_FRAMING_MODE was added to the enum enum dbg_status however there is a missing corresponding entry for this in the array s_status_str. This causes an out-of-bounds read when indexing into the last entry of s_status_str. Fix this by adding in the missing entry. Addresses-Coverity: ("Out-of-bounds read"). Fixes: 2d22bc8354b1 ("qed: FW 8.42.2.0 debug features") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24Merge branch 'net-phy-call-phy_disable_interrupts-in-phy_init_hw'David S. Miller
Jisheng Zhang says: ==================== net: phy: call phy_disable_interrupts() in phy_init_hw() We face an issue with rtl8211f, a pin is shared between INTB and PMEB, and the PHY Register Accessible Interrupt is enabled by default, so the INTB/PMEB pin is always active in polling mode case. As Heiner pointed out "I was thinking about calling phy_disable_interrupts() in phy_init_hw(), to have a defined init state as we don't know in which state the PHY is if the PHY driver is loaded. We shouldn't assume that it's the chip power-on defaults, BIOS or boot loader could have changed this. Or in case of dual-boot systems the other OS could leave the PHY in whatever state." patch1 makes phy_disable_interrupts() non-static so that it could be used in phy_init_hw() to have a defined init state. patch2 calls phy_disable_interrupts() in phy_init_hw() to have a defined init state. Since v3: - call phy_disable_interrupts() have interrupts disabled first then config_init, thank Florian Since v2: - Don't export phy_disable_interrupts() but just make it non-static Since v1: - EXPORT the correct symbol ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24net: phy: call phy_disable_interrupts() in phy_init_hw()Jisheng Zhang
Call phy_disable_interrupts() in phy_init_hw() to "have a defined init state as we don't know in which state the PHY is if the PHY driver is loaded. We shouldn't assume that it's the chip power-on defaults, BIOS or boot loader could have changed this. Or in case of dual-boot systems the other OS could leave the PHY in whatever state." as pointed out by Heiner. Suggested-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24net: phy: make phy_disable_interrupts() non-staticJisheng Zhang
We face an issue with rtl8211f, a pin is shared between INTB and PMEB, and the PHY Register Accessible Interrupt is enabled by default, so the INTB/PMEB pin is always active in polling mode case. As Heiner pointed out "I was thinking about calling phy_disable_interrupts() in phy_init_hw(), to have a defined init state as we don't know in which state the PHY is if the PHY driver is loaded. We shouldn't assume that it's the chip power-on defaults, BIOS or boot loader could have changed this. Or in case of dual-boot systems the other OS could leave the PHY in whatever state." Make phy_disable_interrupts() non-static so that it could be used in phy_init_hw() to have a defined init state. Suggested-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24net: ethernet: mvneta: Add back interface mode validationSascha Hauer
When writing the serdes configuration register was moved to mvneta_config_interface() the whole code block was removed from mvneta_port_power_up() in the assumption that its only purpose was to write the serdes configuration register. As mentioned by Russell King its purpose was also to check for valid interface modes early so that later in the driver we do not have to care for unexpected interface modes. Add back the test to let the driver bail out early on unhandled interface modes. Fixes: b4748553f53f ("net: ethernet: mvneta: Fix Serdes configuration for SoCs without comphy") Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24net: ethernet: mvneta: Do not error out in non serdes modesSascha Hauer
In mvneta_config_interface() the RGMII modes are catched by the default case which is an error return. The RGMII modes are valid modes for the driver, so instead of returning an error add a break statement to return successfully. This avoids this warning for non comphy SoCs which use RGMII, like SolidRun Clearfog: WARNING: CPU: 0 PID: 268 at drivers/net/ethernet/marvell/mvneta.c:3512 mvneta_start_dev+0x220/0x23c Fixes: b4748553f53f ("net: ethernet: mvneta: Fix Serdes configuration for SoCs without comphy") Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24dsa: Allow forwarding of redirected IGMP trafficDaniel Mack
The driver for Marvell switches puts all ports in IGMP snooping mode which results in all IGMP/MLD frames that ingress on the ports to be forwarded to the CPU only. The bridge code in the kernel can then interpret these frames and act upon them, for instance by updating the mdb in the switch to reflect multicast memberships of stations connected to the ports. However, the IGMP/MLD frames must then also be forwarded to other ports of the bridge so external IGMP queriers can track membership reports, and external multicast clients can receive query reports from foreign IGMP queriers. Currently, this is impossible as the EDSA tagger sets offload_fwd_mark on the skb when it unwraps the tagged frames, and that will make the switchdev layer prevent the skb from egressing on any other port of the same switch. To fix that, look at the To_CPU code in the DSA header and make forwarding of the frame possible for trapped IGMP packets. Introduce some #defines for the frame types to make the code a bit more comprehensive. This was tested on a Marvell 88E6352 variant. Signed-off-by: Daniel Mack <daniel@zonque.org> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24openvswitch: take into account de-fragmentation/gso_size in ↵Lorenzo Bianconi
execute_check_pkt_len ovs connection tracking module performs de-fragmentation on incoming fragmented traffic. Take info account if traffic has been de-fragmented in execute_check_pkt_len action otherwise we will perform the wrong nested action considering the original packet size. This issue typically occurs if ovs-vswitchd adds a rule in the pipeline that requires connection tracking (e.g. OVN stateful ACLs) before execute_check_pkt_len action. Moreover take into account GSO fragment size for GSO packet in execute_check_pkt_len routine Fixes: 4d5ec89fc8d14 ("net: openvswitch: Add a new action check_pkt_len") Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-24Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio fixes from Michael Tsirkin: "Fixes all over the place. This includes a couple of tests that I would normally defer, but since they have already been helpful in catching some bugs, don't build for any users at all, and having them upstream makes life easier for everyone, I think it's ok even at this late stage" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: tools/virtio: Use tools/include/list.h instead of stubs tools/virtio: Reset index in virtio_test --reset. tools/virtio: Extract virtqueue initialization in vq_reset tools/virtio: Use __vring_new_virtqueue in virtio_test.c tools/virtio: Add --reset tools/virtio: Add --batch=random option tools/virtio: Add --batch option virtio-mem: add memory via add_memory_driver_managed() virtio-mem: silence a static checker warning vhost_vdpa: Fix potential underflow in vhost_vdpa_mmap() vdpa: fix typos in the comments for __vdpa_alloc_device()
2020-06-24Merge tag 'for-linus-2020-06-24' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull thread fix from Christian Brauner: "This fixes a regression introduced with 303cc571d107 ("nsproxy: attach to namespaces via pidfds"). The LTP testsuite reported a regression where users would now see EBADF returned instead of EINVAL when an fd was passed that referred to an open file but the file was not a namespace file. Fix this by continuing to report EINVAL and add a regression test" * tag 'for-linus-2020-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: tests: test for setns() EINVAL regression nsproxy: restore EINVAL for non-namespace file descriptor
2020-06-24drm/fb-helper: Fix vt restoreDaniel Vetter
In the past we had a pile of hacks to orchestrate access between fbdev emulation and native kms clients. We've tried to streamline this, by always preferring the kms side above fbdev calls when a drm master exists, because drm master controls access to the display resources. Unfortunately this breaks existing userspace, specifically Xorg. When exiting Xorg first restores the console to text mode using the KDSET ioctl on the vt. This does nothing, because a drm master is still around. Then it drops the drm master status, which again does nothing, because logind is keeping additional drm fd open to be able to orchestrate vt switches. In the past this is the point where fbdev was restored, as part of the ->lastclose hook on the drm side. Now to fix this regression we don't want to go back to letting fbdev restore things whenever it feels like, or to the pile of hacks we've had before. Instead try and go with a minimal exception to make the KDSET case work again, and nothing else. This means that if userspace does a KDSET call when switching between graphical compositors, there will be some flickering with fbcon showing up for a bit. But a) that's not a regression and b) userspace can fix it by improving the vt switching dance - logind should have all the information it needs. While pondering all this I'm also wondering wheter we should have a SWITCH_MASTER ioctl to allow race-free master status handover. But that's for another day. v2: Somehow forgot to cc all the fbdev people. v3: Fix typo Alex spotted. Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=208179 Cc: shlomo@fastmail.com Reported-and-Tested-by: shlomo@fastmail.com Cc: Michel Dänzer <michel@daenzer.net> Fixes: 64914da24ea9 ("drm/fbdev-helper: don't force restores") Cc: Noralf Trønnes <noralf@tronnes.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: dri-devel@lists.freedesktop.org Cc: <stable@vger.kernel.org> # v5.7+ Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Qiujun Huang <hqjagain@gmail.com> Cc: Peter Rosin <peda@axentia.se> Cc: linux-fbdev@vger.kernel.org Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200624092910.3280448-1-daniel.vetter@ffwll.ch
2020-06-24IB/hfi1: Add atomic triggered sleep/wakeupMike Marciniszyn
When running iperf in a two host configuration the following trace can occur: [ 319.728730] NETDEV WATCHDOG: ib0 (hfi1): transmit queue 0 timed out The issue happens because the current implementation relies on the netif txq being stopped to control the flushing of the tx list. There are two resources that the transmit logic can wait on and stop the txq: - SDMA descriptors - Ring space to hold completions The ring space is tested on the sending side and relieved when the ring is consumed in the napi tx reaping. Unfortunately, that reaping can run conncurrently with the workqueue flushing of the txlist. If the txq is started just before the workitem executes, the txlist will never be flushed, leading to the txq being stuck. Fix by: - Adding sleep/wakeup wrappers * Use an atomic to control the call to the netif routines inside the wrappers - Use another atomic to record ring space exhaustion * Only wakeup when the a ring space exhaustion has happened and it relieved Add additional wrappers to clarify the ring space resource handling. Fixes: d99dc602e2a5 ("IB/hfi1: Add functions to transmit datagram ipoib packets") Link: https://lore.kernel.org/r/20200623204327.108092.4024.stgit@awfm-01.aw.intel.com Reviewed-by: Kaike Wan <kaike.wan@intel.com> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-06-24IB/hfi1: Correct -EBUSY handling in tx codeMike Marciniszyn
The current code mishandles -EBUSY in two ways: - The flow change doesn't test the return from the flush and runs on to process the current packet racing with the wakeup processing - The -EBUSY handling for a single packet inserts the tx into the txlist after the submit call, racing with the same wakeup processing Fix the first by dropping the skb and returning NETDEV_TX_OK. Fix the second by insuring the the list entry within the txreq is inited when allocated. This enables the sleep routine to detect that the txreq has used the non-list api and queue the packet to the txlist. Both flaws can lead to having the flushing thread executing in causing two threads to manipulate the txlist. Fixes: d99dc602e2a5 ("IB/hfi1: Add functions to transmit datagram ipoib packets") Link: https://lore.kernel.org/r/20200623204321.108092.83898.stgit@awfm-01.aw.intel.com Reviewed-by: Kaike Wan <kaike.wan@intel.com> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-06-24IB/hfi1: Fix module use count flaw due to leftover module put callsDennis Dalessandro
When the try_module_get calls were removed from opening and closing of the i2c debugfs file, the corresponding module_put calls were missed. This results in an inaccurate module use count that requires a power cycle to fix. Fixes: 09fbca8e6240 ("IB/hfi1: No need to use try_module_get for debugfs") Link: https://lore.kernel.org/r/20200623203230.106975.76240.stgit@awfm-01.aw.intel.com Cc: <stable@vger.kernel.org> Reviewed-by: Kaike Wan <kaike.wan@intel.com> Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-06-24IB/hfi1: Restore kfree in dummy_netdev cleanupDennis Dalessandro
We need to do some rework on the dummy netdev. Calling the free_netdev() would normally make sense, and that will be addressed in an upcoming patch. For now just revert the behavior to what it was before keeping the unused variable removal part of the patch. The dd->dumm_netdev is mainly used for packet receiving through alloc_netdev_mqs() for typical net devices. A a result, it should be freed with kfree instead of free_netdev() that leads to a crash when unloading the hfi1 module: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 8000000855b54067 P4D 8000000855b54067 PUD 84a4f5067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 73 PID: 10299 Comm: modprobe Not tainted 5.6.0-rc5+ #1 Hardware name: Intel Corporation S2600WT2R/S2600WT2R, BIOS SE5C610.86B.01.01.0016.033120161139 03/31/2016 RIP: 0010:__hw_addr_flush+0x12/0x80 Code: 40 00 48 83 c4 08 4c 89 e7 5b 5d 41 5c e9 76 77 18 00 66 0f 1f 44 00 00 0f 1f 44 00 00 41 54 49 89 fc 55 53 48 8b 1f 48 39 df <48> 8b 2b 75 08 eb 4a 48 89 eb 48 89 c5 48 89 df e8 99 bf d0 ff 84 RSP: 0018:ffffb40e08783db8 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: ffffb40e00000000 RSI: 0000000000000246 RDI: ffff88ab13662298 RBP: ffff88ab13662000 R08: 0000000000001549 R09: 0000000000001549 R10: 0000000000000001 R11: 0000000000aaaaaa R12: ffff88ab13662298 R13: ffff88ab1b259e20 R14: ffff88ab1b259e42 R15: 0000000000000000 FS: 00007fb39b534740(0000) GS:ffff88b31f940000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000084d3ea004 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dev_addr_flush+0x15/0x30 free_netdev+0x7e/0x130 hfi1_netdev_free+0x59/0x70 [hfi1] remove_one+0x65/0x110 [hfi1] pci_device_remove+0x3b/0xc0 device_release_driver_internal+0xec/0x1b0 driver_detach+0x46/0x90 bus_remove_driver+0x58/0xd0 pci_unregister_driver+0x26/0xa0 hfi1_mod_cleanup+0xc/0xd54 [hfi1] __x64_sys_delete_module+0x16c/0x260 ? exit_to_usermode_loop+0xa4/0xc0 do_syscall_64+0x5b/0x200 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 193ba03141bb ("IB/hfi1: Use free_netdev() in hfi1_netdev_free()") Link: https://lore.kernel.org/r/20200623203224.106975.16926.stgit@awfm-01.aw.intel.com Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Kaike Wan <kaike.wan@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-06-24hwmon: (max6697) Make sure the OVERT mask is set correctlyChu Lin
Per the datasheet for max6697, OVERT mask and ALERT mask are different. For example, the 7th bit of OVERT is the local channel but for alert mask, the 6th bit is the local channel. Therefore, we can't apply the same mask for both registers. In addition to that, the max6697 driver is supposed to be compatibale with different models. I manually went over all the listed chips and made sure all chip types have the same layout. Testing; mask value of 0x9 should map to 0x44 for ALERT and 0x84 for OVERT. I used iotool to read the reg value back to verify. I only tested this change on max6581. Reference: https://datasheets.maximintegrated.com/en/ds/MAX6581.pdf https://datasheets.maximintegrated.com/en/ds/MAX6697.pdf https://datasheets.maximintegrated.com/en/ds/MAX6699.pdf Signed-off-by: Chu Lin <linchuyuan@google.com> Fixes: 5372d2d71c46e ("hwmon: Driver for Maxim MAX6697 and compatibles") Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2020-06-24nvme-multipath: fix bogus request queue reference putSagi Grimberg
The mpath disk node takes a reference on the request mpath request queue when adding live path to the mpath gendisk. However if we connected to an inaccessible path device_add_disk is not called, so if we disconnect and remove the mpath gendisk we endup putting an reference on the request queue that was never taken [1]. Fix that to check if we ever added a live path (using NVME_NS_HEAD_HAS_DISK flag) and if not, clear the disk->queue reference. [1]: ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 1372 at lib/refcount.c:28 refcount_warn_saturate+0xa6/0xf0 CPU: 1 PID: 1372 Comm: nvme Tainted: G O 5.7.0-rc2+ #3 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1 04/01/2014 RIP: 0010:refcount_warn_saturate+0xa6/0xf0 RSP: 0018:ffffb29e8053bdc0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff8b7a2f4fc060 RCX: 0000000000000007 RDX: 0000000000000007 RSI: 0000000000000092 RDI: ffff8b7a3ec99980 RBP: ffff8b7a2f4fc000 R08: 00000000000002e1 R09: 0000000000000004 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: fffffffffffffff2 R14: ffffb29e8053bf08 R15: ffff8b7a320e2da0 FS: 00007f135d4ca800(0000) GS:ffff8b7a3ec80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005651178c0c30 CR3: 000000003b650005 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: disk_release+0xa2/0xc0 device_release+0x28/0x80 kobject_put+0xa5/0x1b0 nvme_put_ns_head+0x26/0x70 [nvme_core] nvme_put_ns+0x30/0x60 [nvme_core] nvme_remove_namespaces+0x9b/0xe0 [nvme_core] nvme_do_delete_ctrl+0x43/0x5c [nvme_core] nvme_sysfs_delete.cold+0x8/0xd [nvme_core] kernfs_fop_write+0xc1/0x1a0 vfs_write+0xb6/0x1a0 ksys_write+0x5f/0xe0 do_syscall_64+0x52/0x1a0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported-by: Anton Eidelman <anton@lightbitslabs.com> Tested-by: Anton Eidelman <anton@lightbitslabs.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-24nvme-multipath: fix deadlock due to head->lockAnton Eidelman
In the following scenario scan_work and ana_work will deadlock: When scan_work calls nvme_mpath_add_disk() this holds ana_lock and invokes nvme_parse_ana_log(), which may issue IO in device_add_disk() and hang waiting for an accessible path. While nvme_mpath_set_live() only called when nvme_state_is_live(), a transition may cause NVME_SC_ANA_TRANSITION and requeue the IO. Since nvme_mpath_set_live() holds ns->head->lock, an ana_work on ANY ctrl will not be able to complete nvme_mpath_set_live() on the same ns->head, which is required in order to update the new accessible path and remove NVME_NS_ANA_PENDING.. Therefore IO never completes: deadlock [1]. Fix: Move device_add_disk out of the head->lock and protect it with an atomic test_and_set for a new NVME_NS_HEAD_HAS_DISK bit. [1]: kernel: INFO: task kworker/u8:2:160 blocked for more than 120 seconds. kernel: Tainted: G OE 5.3.5-050305-generic #201910071830 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: kworker/u8:2 D 0 160 2 0x80004000 kernel: Workqueue: nvme-wq nvme_ana_work [nvme_core] kernel: Call Trace: kernel: __schedule+0x2b9/0x6c0 kernel: schedule+0x42/0xb0 kernel: schedule_preempt_disabled+0xe/0x10 kernel: __mutex_lock.isra.0+0x182/0x4f0 kernel: __mutex_lock_slowpath+0x13/0x20 kernel: mutex_lock+0x2e/0x40 kernel: nvme_update_ns_ana_state+0x22/0x60 [nvme_core] kernel: nvme_update_ana_state+0xca/0xe0 [nvme_core] kernel: nvme_parse_ana_log+0xa1/0x180 [nvme_core] kernel: nvme_read_ana_log+0x76/0x100 [nvme_core] kernel: nvme_ana_work+0x15/0x20 [nvme_core] kernel: process_one_work+0x1db/0x380 kernel: worker_thread+0x4d/0x400 kernel: kthread+0x104/0x140 kernel: ret_from_fork+0x35/0x40 kernel: INFO: task kworker/u8:4:439 blocked for more than 120 seconds. kernel: Tainted: G OE 5.3.5-050305-generic #201910071830 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: kworker/u8:4 D 0 439 2 0x80004000 kernel: Workqueue: nvme-wq nvme_scan_work [nvme_core] kernel: Call Trace: kernel: __schedule+0x2b9/0x6c0 kernel: schedule+0x42/0xb0 kernel: io_schedule+0x16/0x40 kernel: do_read_cache_page+0x438/0x830 kernel: read_cache_page+0x12/0x20 kernel: read_dev_sector+0x27/0xc0 kernel: read_lba+0xc1/0x220 kernel: efi_partition+0x1e6/0x708 kernel: check_partition+0x154/0x244 kernel: rescan_partitions+0xae/0x280 kernel: __blkdev_get+0x40f/0x560 kernel: blkdev_get+0x3d/0x140 kernel: __device_add_disk+0x388/0x480 kernel: device_add_disk+0x13/0x20 kernel: nvme_mpath_set_live+0x119/0x140 [nvme_core] kernel: nvme_update_ns_ana_state+0x5c/0x60 [nvme_core] kernel: nvme_mpath_add_disk+0xbe/0x100 [nvme_core] kernel: nvme_validate_ns+0x396/0x940 [nvme_core] kernel: nvme_scan_work+0x256/0x390 [nvme_core] kernel: process_one_work+0x1db/0x380 kernel: worker_thread+0x4d/0x400 kernel: kthread+0x104/0x140 kernel: ret_from_fork+0x35/0x40 Fixes: 0d0b660f214d ("nvme: add ANA support") Signed-off-by: Anton Eidelman <anton@lightbitslabs.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-24nvme: don't protect ns mutation with ns->head->lockSagi Grimberg
Right now ns->head->lock is protecting namespace mutation which is wrong and unneeded. Move it to only protect against head mutations. While we're at it, remove unnecessary ns->head reference as we already have head pointer. The problem with this is that the head->lock spans mpath disk node I/O that may block under some conditions (if for example the controller is disconnecting or the path became inaccessible), The locking scheme does not allow any other path to enable itself, preventing blocked I/O to complete and forward-progress from there. This is a preparation patch for the fix in a subsequent patch where the disk I/O will also be done outside the head->lock. Fixes: 0d0b660f214d ("nvme: add ANA support") Signed-off-by: Anton Eidelman <anton@lightbitslabs.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-24nvme-multipath: fix deadlock between ana_work and scan_workAnton Eidelman
When scan_work calls nvme_mpath_add_disk() this holds ana_lock and invokes nvme_parse_ana_log(), which may issue IO in device_add_disk() and hang waiting for an accessible path. While nvme_mpath_set_live() only called when nvme_state_is_live(), a transition may cause NVME_SC_ANA_TRANSITION and requeue the IO. In order to recover and complete the IO ana_work on the same ctrl should be able to update the path state and remove NVME_NS_ANA_PENDING. The deadlock occurs because scan_work keeps holding ana_lock, so ana_work hangs [1]. Fix: Now nvme_mpath_add_disk() uses nvme_parse_ana_log() to obtain a copy of the ANA group desc, and then calls nvme_update_ns_ana_state() without holding ana_lock. [1]: kernel: Workqueue: nvme-wq nvme_scan_work [nvme_core] kernel: Call Trace: kernel: __schedule+0x2b9/0x6c0 kernel: schedule+0x42/0xb0 kernel: io_schedule+0x16/0x40 kernel: do_read_cache_page+0x438/0x830 kernel: read_cache_page+0x12/0x20 kernel: read_dev_sector+0x27/0xc0 kernel: read_lba+0xc1/0x220 kernel: efi_partition+0x1e6/0x708 kernel: check_partition+0x154/0x244 kernel: rescan_partitions+0xae/0x280 kernel: __blkdev_get+0x40f/0x560 kernel: blkdev_get+0x3d/0x140 kernel: __device_add_disk+0x388/0x480 kernel: device_add_disk+0x13/0x20 kernel: nvme_mpath_set_live+0x119/0x140 [nvme_core] kernel: nvme_update_ns_ana_state+0x5c/0x60 [nvme_core] kernel: nvme_set_ns_ana_state+0x1e/0x30 [nvme_core] kernel: nvme_parse_ana_log+0xa1/0x180 [nvme_core] kernel: nvme_mpath_add_disk+0x47/0x90 [nvme_core] kernel: nvme_validate_ns+0x396/0x940 [nvme_core] kernel: nvme_scan_work+0x24f/0x380 [nvme_core] kernel: process_one_work+0x1db/0x380 kernel: worker_thread+0x249/0x400 kernel: kthread+0x104/0x140 kernel: Workqueue: nvme-wq nvme_ana_work [nvme_core] kernel: Call Trace: kernel: __schedule+0x2b9/0x6c0 kernel: schedule+0x42/0xb0 kernel: schedule_preempt_disabled+0xe/0x10 kernel: __mutex_lock.isra.0+0x182/0x4f0 kernel: ? __switch_to_asm+0x34/0x70 kernel: ? select_task_rq_fair+0x1aa/0x5c0 kernel: ? kvm_sched_clock_read+0x11/0x20 kernel: ? sched_clock+0x9/0x10 kernel: __mutex_lock_slowpath+0x13/0x20 kernel: mutex_lock+0x2e/0x40 kernel: nvme_read_ana_log+0x3a/0x100 [nvme_core] kernel: nvme_ana_work+0x15/0x20 [nvme_core] kernel: process_one_work+0x1db/0x380 kernel: worker_thread+0x4d/0x400 kernel: kthread+0x104/0x140 kernel: ? process_one_work+0x380/0x380 kernel: ? kthread_park+0x80/0x80 kernel: ret_from_fork+0x35/0x40 Fixes: 0d0b660f214d ("nvme: add ANA support") Signed-off-by: Anton Eidelman <anton@lightbitslabs.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-24nvme: fix possible deadlock when I/O is blockedSagi Grimberg
Revert fab7772bfbcf ("nvme-multipath: revalidate nvme_ns_head gendisk in nvme_validate_ns") When adding a new namespace to the head disk (via nvme_mpath_set_live) we will see partition scan which triggers I/O on the mpath device node. This process will usually be triggered from the scan_work which holds the scan_lock. If I/O blocks (if we got ana change currently have only available paths but none are accessible) this can deadlock on the head disk bd_mutex as both partition scan I/O takes it, and head disk revalidation takes it to check for resize (also triggered from scan_work on a different path). See trace [1]. The mpath disk revalidation was originally added to detect online disk size change, but this is no longer needed since commit cb224c3af4df ("nvme: Convert to use set_capacity_revalidate_and_notify") which already updates resize info without unnecessarily revalidating the disk (the mpath disk doesn't even implement .revalidate_disk fop). [1]: -- kernel: INFO: task kworker/u65:9:494 blocked for more than 241 seconds. kernel: Tainted: G OE 5.3.5-050305-generic #201910071830 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: kworker/u65:9 D 0 494 2 0x80004000 kernel: Workqueue: nvme-wq nvme_scan_work [nvme_core] kernel: Call Trace: kernel: __schedule+0x2b9/0x6c0 kernel: schedule+0x42/0xb0 kernel: schedule_preempt_disabled+0xe/0x10 kernel: __mutex_lock.isra.0+0x182/0x4f0 kernel: __mutex_lock_slowpath+0x13/0x20 kernel: mutex_lock+0x2e/0x40 kernel: revalidate_disk+0x63/0xa0 kernel: __nvme_revalidate_disk+0xfe/0x110 [nvme_core] kernel: nvme_revalidate_disk+0xa4/0x160 [nvme_core] kernel: ? evict+0x14c/0x1b0 kernel: revalidate_disk+0x2b/0xa0 kernel: nvme_validate_ns+0x49/0x940 [nvme_core] kernel: ? blk_mq_free_request+0xd2/0x100 kernel: ? __nvme_submit_sync_cmd+0xbe/0x1e0 [nvme_core] kernel: nvme_scan_work+0x24f/0x380 [nvme_core] kernel: process_one_work+0x1db/0x380 kernel: worker_thread+0x249/0x400 kernel: kthread+0x104/0x140 kernel: ? process_one_work+0x380/0x380 kernel: ? kthread_park+0x80/0x80 kernel: ret_from_fork+0x1f/0x40 ... kernel: INFO: task kworker/u65:1:2630 blocked for more than 241 seconds. kernel: Tainted: G OE 5.3.5-050305-generic #201910071830 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: kworker/u65:1 D 0 2630 2 0x80004000 kernel: Workqueue: nvme-wq nvme_scan_work [nvme_core] kernel: Call Trace: kernel: __schedule+0x2b9/0x6c0 kernel: schedule+0x42/0xb0 kernel: io_schedule+0x16/0x40 kernel: do_read_cache_page+0x438/0x830 kernel: ? __switch_to_asm+0x34/0x70 kernel: ? file_fdatawait_range+0x30/0x30 kernel: read_cache_page+0x12/0x20 kernel: read_dev_sector+0x27/0xc0 kernel: read_lba+0xc1/0x220 kernel: ? kmem_cache_alloc_trace+0x19c/0x230 kernel: efi_partition+0x1e6/0x708 kernel: ? vsnprintf+0x39e/0x4e0 kernel: ? snprintf+0x49/0x60 kernel: check_partition+0x154/0x244 kernel: rescan_partitions+0xae/0x280 kernel: __blkdev_get+0x40f/0x560 kernel: blkdev_get+0x3d/0x140 kernel: __device_add_disk+0x388/0x480 kernel: device_add_disk+0x13/0x20 kernel: nvme_mpath_set_live+0x119/0x140 [nvme_core] kernel: nvme_update_ns_ana_state+0x5c/0x60 [nvme_core] kernel: nvme_set_ns_ana_state+0x1e/0x30 [nvme_core] kernel: nvme_parse_ana_log+0xa1/0x180 [nvme_core] kernel: ? nvme_update_ns_ana_state+0x60/0x60 [nvme_core] kernel: nvme_mpath_add_disk+0x47/0x90 [nvme_core] kernel: nvme_validate_ns+0x396/0x940 [nvme_core] kernel: ? blk_mq_free_request+0xd2/0x100 kernel: nvme_scan_work+0x24f/0x380 [nvme_core] kernel: process_one_work+0x1db/0x380 kernel: worker_thread+0x249/0x400 kernel: kthread+0x104/0x140 kernel: ? process_one_work+0x380/0x380 kernel: ? kthread_park+0x80/0x80 kernel: ret_from_fork+0x1f/0x40 -- Fixes: fab7772bfbcf ("nvme-multipath: revalidate nvme_ns_head gendisk in nvme_validate_ns") Signed-off-by: Anton Eidelman <anton@lightbitslabs.com> Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-24nvme-rdma: assign completion vector correctlyMax Gurtovoy
The completion vector index that is given during CQ creation can't exceed the number of support vectors by the underlying RDMA device. This violation currently can accure, for example, in case one will try to connect with N regular read/write queues and M poll queues and the sum of N + M > num_supported_vectors. This will lead to failure in establish a connection to remote target. Instead, in that case, share a completion vector between queues. Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-24nvme-loop: initialize tagset numa value to the value of the ctrlMax Gurtovoy
Both admin's and drive's tagsets should be set according the numa node of the controller. Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-24nvme-tcp: initialize tagset numa value to the value of the ctrlMax Gurtovoy
Both admin's and drive's tagsets should be set according the numa node of the controller. Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-24nvme-pci: initialize tagset numa value to the value of the ctrlMax Gurtovoy
Both admin's and drive's tagsets should be set according the numa node of the controller. Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-24nvme-pci: override the value of the controller's numa nodeMax Gurtovoy
Set the node value according to the PCI device numa node. Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-24nvme: set initial value for controller's numa nodeMax Gurtovoy
Initialize the node to NUMA_NO_NODE value. Transports that are aware of numa node affinity can override it (e.g. RDMA transport set the affinity according to the RDMA HCA). Signed-off-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-06-24block: move struct block_device to blk_types.hChristoph Hellwig
Move the struct block_device definition together with most of the block layer definitions, as it has nothing to do with the rest of fs.h. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24block: reduce ifdef CONFIG_BLOCK madness in headersChristoph Hellwig
Large part of bio.h, blkdev.h and genhd.h are under ifdef CONFIG_BLOCK for no good reason. Only stub out function that are called from code that is not dependent on CONFIG_BLOCK and leave the harmless other declarations around. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24fs: move the buffer_heads_over_limit stub to buffer_head.hChristoph Hellwig
Move the !CONFIG_BLOCK stub to the same place as the non-stub declaration. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24block: move block-related definitions out of fs.hChristoph Hellwig
Move most of the block related definition out of fs.h into more suitable headers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24block: simplify sb_is_blkdev_sbChristoph Hellwig
Just use IS_ENABLED instead of providing a stub for !CONFIG_BLOCK. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24fs: remove the mount_bdev and kill_block_super stubsChristoph Hellwig
No one calls these functions without CONFIG_BLOCK, so don't bother stubbing them out. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24fs: remove the HAVE_UNLOCKED_IOCTL and HAVE_COMPAT_IOCTL definesChristoph Hellwig
These are not defined anywhere, and contrary to the comments we really do not care about out of tree code at all. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24fs: remove an unused block_device_operations forward declarationChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24block: mark bd_finish_claiming staticChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24tty/sysrq: emergency_thaw_all does not depend on CONFIG_BLOCKChristoph Hellwig
We can also thaw non-block file systems. Remove the CONFIG_BLOCK in sysrq.c after making the prototype available unconditionally. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24nvme-rdma: fix a missing completion with remove invalidationChristoph Hellwig
Revert and incorret transformation that caused requests using remote invalidation to never complete. Fixes: 421147be863b ("nvme-rdma: factor out a nvme_rdma_end_request helper") Reported-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24blk-iocost: Use struct_size() in kzalloc_node()Gustavo A. R. Silva
Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. This code was detected with the help of Coccinelle and, audited and fixed manually. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Addresses-KSPP-ID: https://github.com/KSPP/linux/issues/83 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24block: bio: Use struct_size() in kmalloc()Gustavo A. R. Silva
Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. This code was detected with the help of Coccinelle and, audited and fixed manually. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Addresses-KSPP-ID: https://github.com/KSPP/linux/issues/83 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24block: create the request_queue debugfs_dir on registrationLuis Chamberlain
We were only creating the request_queue debugfs_dir only for make_request block drivers (multiqueue), but never for request-based block drivers. We did this as we were only creating non-blktrace additional debugfs files on that directory for make_request drivers. However, since blktrace *always* creates that directory anyway, we special-case the use of that directory on blktrace. Other than this being an eye-sore, this exposes request-based block drivers to the same debugfs fragile race that used to exist with make_request block drivers where if we start adding files onto that directory we can later run a race with a double removal of dentries on the directory if we don't deal with this carefully on blktrace. Instead, just simplify things by always creating the request_queue debugfs_dir on request_queue registration. Rename the mutex also to reflect the fact that this is used outside of the blktrace context. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24blktrace: ensure our debugfs dir existsLuis Chamberlain
We make an assumption that a debugfs directory exists, but since this can fail ensure it exists before allowing blktrace setup to complete. Otherwise we end up stuffing blktrace files on the debugfs root directory. In the worst case scenario this *in theory* can create an eventual panic *iff* in the future a similarly named file is created prior on the debugfs root directory. This theoretical crash can happen due to a recursive removal followed by a specific dentry removal. This doesn't fix any known crash, however I have seen the files go into the main debugfs root directory in cases where the debugfs directory was not created due to other internal bugs with blktrace now fixed. blktrace is also completely useless without this directory, so this ensures to userspace we only setup blktrace if the kernel can stuff files where they are supposed to go into. debugfs directory creations typically aren't checked for, and we have maintainers doing sweep removals of these checks, but since we need this check to ensure proper userspace blktrace functionality we make sure to annotate the justification for the check. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-24blktrace: fix debugfs use after freeLuis Chamberlain
On commit 6ac93117ab00 ("blktrace: use existing disk debugfs directory") merged on v4.12 Omar fixed the original blktrace code for request-based drivers (multiqueue). This however left in place a possible crash, if you happen to abuse blktrace while racing to remove / add a device. We used to use asynchronous removal of the request_queue, and with that the issue was easier to reproduce. Now that we have reverted to synchronous removal of the request_queue, the issue is still possible to reproduce, its however just a bit more difficult. We essentially run two instances of break-blktrace which add/remove a loop device, and setup a blktrace and just never tear the blktrace down. We do this twice in parallel. This is easily reproduced with the script run_0004.sh from break-blktrace [0]. We can end up with two types of panics each reflecting where we race, one a failed blktrace setup: [ 252.426751] debugfs: Directory 'loop0' with parent 'block' already present! [ 252.432265] BUG: kernel NULL pointer dereference, address: 00000000000000a0 [ 252.436592] #PF: supervisor write access in kernel mode [ 252.439822] #PF: error_code(0x0002) - not-present page [ 252.442967] PGD 0 P4D 0 [ 252.444656] Oops: 0002 [#1] SMP NOPTI [ 252.446972] CPU: 10 PID: 1153 Comm: break-blktrace Tainted: G E 5.7.0-rc2-next-20200420+ #164 [ 252.452673] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 [ 252.456343] RIP: 0010:down_write+0x15/0x40 [ 252.458146] Code: eb ca e8 ae 22 8d ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 55 48 89 fd e8 52 db ff ff 31 c0 ba 01 00 00 00 <f0> 48 0f b1 55 00 75 0f 48 8b 04 25 c0 8b 01 00 48 89 45 08 5d [ 252.463638] RSP: 0018:ffffa626415abcc8 EFLAGS: 00010246 [ 252.464950] RAX: 0000000000000000 RBX: ffff958c25f0f5c0 RCX: ffffff8100000000 [ 252.466727] RDX: 0000000000000001 RSI: ffffff8100000000 RDI: 00000000000000a0 [ 252.468482] RBP: 00000000000000a0 R08: 0000000000000000 R09: 0000000000000001 [ 252.470014] R10: 0000000000000000 R11: ffff958d1f9227ff R12: 0000000000000000 [ 252.471473] R13: ffff958c25ea5380 R14: ffffffff8cce15f1 R15: 00000000000000a0 [ 252.473346] FS: 00007f2e69dee540(0000) GS:ffff958c2fc80000(0000) knlGS:0000000000000000 [ 252.475225] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 252.476267] CR2: 00000000000000a0 CR3: 0000000427d10004 CR4: 0000000000360ee0 [ 252.477526] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 252.478776] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 252.479866] Call Trace: [ 252.480322] simple_recursive_removal+0x4e/0x2e0 [ 252.481078] ? debugfs_remove+0x60/0x60 [ 252.481725] ? relay_destroy_buf+0x77/0xb0 [ 252.482662] debugfs_remove+0x40/0x60 [ 252.483518] blk_remove_buf_file_callback+0x5/0x10 [ 252.484328] relay_close_buf+0x2e/0x60 [ 252.484930] relay_open+0x1ce/0x2c0 [ 252.485520] do_blk_trace_setup+0x14f/0x2b0 [ 252.486187] __blk_trace_setup+0x54/0xb0 [ 252.486803] blk_trace_ioctl+0x90/0x140 [ 252.487423] ? do_sys_openat2+0x1ab/0x2d0 [ 252.488053] blkdev_ioctl+0x4d/0x260 [ 252.488636] block_ioctl+0x39/0x40 [ 252.489139] ksys_ioctl+0x87/0xc0 [ 252.489675] __x64_sys_ioctl+0x16/0x20 [ 252.490380] do_syscall_64+0x52/0x180 [ 252.491032] entry_SYSCALL_64_after_hwframe+0x44/0xa9 And the other on the device removal: [ 128.528940] debugfs: Directory 'loop0' with parent 'block' already present! [ 128.615325] BUG: kernel NULL pointer dereference, address: 00000000000000a0 [ 128.619537] #PF: supervisor write access in kernel mode [ 128.622700] #PF: error_code(0x0002) - not-present page [ 128.625842] PGD 0 P4D 0 [ 128.627585] Oops: 0002 [#1] SMP NOPTI [ 128.629871] CPU: 12 PID: 544 Comm: break-blktrace Tainted: G E 5.7.0-rc2-next-20200420+ #164 [ 128.635595] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014 [ 128.640471] RIP: 0010:down_write+0x15/0x40 [ 128.643041] Code: eb ca e8 ae 22 8d ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 55 48 89 fd e8 52 db ff ff 31 c0 ba 01 00 00 00 <f0> 48 0f b1 55 00 75 0f 65 48 8b 04 25 c0 8b 01 00 48 89 45 08 5d [ 128.650180] RSP: 0018:ffffa9c3c05ebd78 EFLAGS: 00010246 [ 128.651820] RAX: 0000000000000000 RBX: ffff8ae9a6370240 RCX: ffffff8100000000 [ 128.653942] RDX: 0000000000000001 RSI: ffffff8100000000 RDI: 00000000000000a0 [ 128.655720] RBP: 00000000000000a0 R08: 0000000000000002 R09: ffff8ae9afd2d3d0 [ 128.657400] R10: 0000000000000056 R11: 0000000000000000 R12: 0000000000000000 [ 128.659099] R13: 0000000000000000 R14: 0000000000000003 R15: 00000000000000a0 [ 128.660500] FS: 00007febfd995540(0000) GS:ffff8ae9afd00000(0000) knlGS:0000000000000000 [ 128.662204] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 128.663426] CR2: 00000000000000a0 CR3: 0000000420042003 CR4: 0000000000360ee0 [ 128.664776] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 128.666022] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 128.667282] Call Trace: [ 128.667801] simple_recursive_removal+0x4e/0x2e0 [ 128.668663] ? debugfs_remove+0x60/0x60 [ 128.669368] debugfs_remove+0x40/0x60 [ 128.669985] blk_trace_free+0xd/0x50 [ 128.670593] __blk_trace_remove+0x27/0x40 [ 128.671274] blk_trace_shutdown+0x30/0x40 [ 128.671935] blk_release_queue+0x95/0xf0 [ 128.672589] kobject_put+0xa5/0x1b0 [ 128.673188] disk_release+0xa2/0xc0 [ 128.673786] device_release+0x28/0x80 [ 128.674376] kobject_put+0xa5/0x1b0 [ 128.674915] loop_remove+0x39/0x50 [loop] [ 128.675511] loop_control_ioctl+0x113/0x130 [loop] [ 128.676199] ksys_ioctl+0x87/0xc0 [ 128.676708] __x64_sys_ioctl+0x16/0x20 [ 128.677274] do_syscall_64+0x52/0x180 [ 128.677823] entry_SYSCALL_64_after_hwframe+0x44/0xa9 The common theme here is: debugfs: Directory 'loop0' with parent 'block' already present This crash happens because of how blktrace uses the debugfs directory where it places its files. Upon init we always create the same directory which would be needed by blktrace but we only do this for make_request drivers (multiqueue) block drivers. When you race a removal of these devices with a blktrace setup you end up in a situation where the make_request recursive debugfs removal will sweep away the blktrace files and then later blktrace will also try to remove individual dentries which are already NULL. The inverse is also possible and hence the two types of use after frees. We don't create the block debugfs directory on init for these types of block devices: * request-based block driver block devices * every possible partition * scsi-generic And so, this race should in theory only be possible with make_request drivers. We can fix the UAF by simply re-using the debugfs directory for make_request drivers (multiqueue) and only creating the ephemeral directory for the other type of block devices. The new clarifications on relying on the q->blk_trace_mutex *and* also checking for q->blk_trace *prior* to processing a blktrace ensures the debugfs directories are only created if no possible directory name clashes are possible. This goes tested with: o nvme partitions o ISCSI with tgt, and blktracing against scsi-generic with: o block o tape o cdrom o media changer o blktests This patch is part of the work which disputes the severity of CVE-2019-19770 which shows this issue is not a core debugfs issue, but a misuse of debugfs within blktace. Fixes: 6ac93117ab00 ("blktrace: use existing disk debugfs directory") Reported-by: syzbot+603294af2d01acfdd6da@syzkaller.appspotmail.com Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Omar Sandoval <osandov@fb.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Nicolai Stange <nstange@suse.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: yu kuai <yukuai3@huawei.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>