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2024-10-30nvmet-auth: assign dh_key to NULL after kfree_sensitiveVitaliy Shevtsov
ctrl->dh_key might be used across multiple calls to nvmet_setup_dhgroup() for the same controller. So it's better to nullify it after release on error path in order to avoid double free later in nvmet_destroy_auth(). Found by Linux Verification Center (linuxtesting.org) with Svace. Fixes: 7a277c37d352 ("nvmet-auth: Diffie-Hellman key exchange support") Cc: stable@vger.kernel.org Signed-off-by: Vitaliy Shevtsov <v.shevtsov@maxima.ru> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-10-30nvme: module parameter to disable pi with offsetsKeith Busch
A recent commit enables integrity checks for formats the previous kernel versions registered with the "nop" integrity profile. This means namespaces using that format become unreadable when upgrading the kernel past that commit. Introduce a module parameter to restore the "nop" integrity profile so that storage can be readable once again. This could be a boot device, so the setting needs to happen at module load time. Fixes: 921e81db524d17 ("nvme: allow integrity when PI is not in first bytes") Reported-by: David Wei <dw@davidwei.uk> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-10-30blk-integrity: remove seed for user mapped buffersKeith Busch
The seed is only used for kernel generation and verification. That doesn't happen for user buffers, so passing the seed around doesn't accomplish anything. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anuj Gupta <anuj20.g@samsung.com> Reviewed-by: Kanchan Joshi <joshi.k@samsung.com> Link: https://lore.kernel.org/r/20241016201309.1090320-1-kbusch@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-30ALSA: hda/realtek: Fix headset mic on TUXEDO Stellaris 16 Gen6 mb1Christoffer Sandberg
Quirk is needed to enable headset microphone on missing pin 0x19. Signed-off-by: Christoffer Sandberg <cs@tuxedo.de> Signed-off-by: Werner Sembach <wse@tuxedocomputers.com> Cc: <stable@vger.kernel.org> Link: https://patch.msgid.link/20241029151653.80726-2-wse@tuxedocomputers.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-10-30ALSA: hda/realtek: Fix headset mic on TUXEDO Gemini 17 Gen3Christoffer Sandberg
Quirk is needed to enable headset microphone on missing pin 0x19. Signed-off-by: Christoffer Sandberg <cs@tuxedo.de> Signed-off-by: Werner Sembach <wse@tuxedocomputers.com> Cc: <stable@vger.kernel.org> Link: https://patch.msgid.link/20241029151653.80726-1-wse@tuxedocomputers.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-10-30ALSA: usb-audio: Add quirks for Dell WD19 dockJan Schär
The WD19 family of docks has the same audio chipset as the WD15. This change enables jack detection on the WD19. We don't need the dell_dock_mixer_init quirk for the WD19. It is only needed because of the dell_alc4020_map quirk for the WD15 in mixer_maps.c, which disables the volume controls. Even for the WD15, this quirk was apparently only needed when the dock firmware was not updated. Signed-off-by: Jan Schär <jan@jschaer.ch> Cc: <stable@vger.kernel.org> Link: https://patch.msgid.link/20241029221249.15661-1-jan@jschaer.ch Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-10-30Merge tag 'asoc-fix-v6.12-rc5' of ↵Takashi Iwai
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus ASoC: Fixes for v6.12 The biggest set of changes here is Hans' fixes and quirks for various Baytrail based platforms with RT5640 CODECs, and there's one core fix for a missed length assignment for __counted_by() checking. Otherwise it's small device specific fixes, several of them in the DT bindings.
2024-10-30brd: defer automatic disk creation until module initialization succeedsYang Erkun
My colleague Wupeng found the following problems during fault injection: BUG: unable to handle page fault for address: fffffbfff809d073 PGD 6e648067 P4D 123ec8067 PUD 123ec4067 PMD 100e38067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 5 UID: 0 PID: 755 Comm: modprobe Not tainted 6.12.0-rc3+ #17 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:__asan_load8+0x4c/0xa0 ... Call Trace: <TASK> blkdev_put_whole+0x41/0x70 bdev_release+0x1a3/0x250 blkdev_release+0x11/0x20 __fput+0x1d7/0x4a0 task_work_run+0xfc/0x180 syscall_exit_to_user_mode+0x1de/0x1f0 do_syscall_64+0x6b/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e loop_init() is calling loop_add() after __register_blkdev() succeeds and is ignoring disk_add() failure from loop_add(), for loop_add() failure is not fatal and successfully created disks are already visible to bdev_open(). brd_init() is currently calling brd_alloc() before __register_blkdev() succeeds and is releasing successfully created disks when brd_init() returns an error. This can cause UAF for the latter two case: case 1: T1: modprobe brd brd_init brd_alloc(0) // success add_disk disk_scan_partitions bdev_file_open_by_dev // alloc file fput // won't free until back to userspace brd_alloc(1) // failed since mem alloc error inject // error path for modprobe will release code segment // back to userspace __fput blkdev_release bdev_release blkdev_put_whole bdev->bd_disk->fops->release // fops is freed now, UAF! case 2: T1: T2: modprobe brd brd_init brd_alloc(0) // success open(/dev/ram0) brd_alloc(1) // fail // error path for modprobe close(/dev/ram0) ... /* UAF! */ bdev->bd_disk->fops->release Fix this problem by following what loop_init() does. Besides, reintroduce brd_devices_mutex to help serialize modifications to brd_list. Fixes: 7f9b348cb5e9 ("brd: convert to blk_alloc_disk/blk_cleanup_disk") Reported-by: Wupeng Ma <mawupeng1@huawei.com> Signed-off-by: Yang Erkun <yangerkun@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20241030034914.907829-1-yangerkun@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-30loop: Use bdev limit helpers for configuring discardJohn Garry
Instead of directly looking at the request_queue limits, use the bdev limits helpers, which is preferable. Signed-off-by: John Garry <john.g.garry@oracle.com> Link: https://lore.kernel.org/r/20241030111900.3981223-1-john.g.garry@oracle.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-30netfilter: nf_reject_ipv6: fix potential crash in nf_send_reset6()Eric Dumazet
I got a syzbot report without a repro [1] crashing in nf_send_reset6() I think the issue is that dev->hard_header_len is zero, and we attempt later to push an Ethernet header. Use LL_MAX_HEADER, as other functions in net/ipv6/netfilter/nf_reject_ipv6.c. [1] skbuff: skb_under_panic: text:ffffffff89b1d008 len:74 put:14 head:ffff88803123aa00 data:ffff88803123a9f2 tail:0x3c end:0x140 dev:syz_tun kernel BUG at net/core/skbuff.c:206 ! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 0 UID: 0 PID: 7373 Comm: syz.1.568 Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:skb_panic net/core/skbuff.c:206 [inline] RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216 Code: 0d 8d 48 c7 c6 60 a6 29 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 ba 30 38 02 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 RSP: 0018:ffffc900045269b0 EFLAGS: 00010282 RAX: 0000000000000088 RBX: dffffc0000000000 RCX: cd66dacdc5d8e800 RDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000000 RBP: ffff88802d39a3d0 R08: ffffffff8174afec R09: 1ffff920008a4ccc R10: dffffc0000000000 R11: fffff520008a4ccd R12: 0000000000000140 R13: ffff88803123aa00 R14: ffff88803123a9f2 R15: 000000000000003c FS: 00007fdbee5ff6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000005d322000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> skb_push+0xe5/0x100 net/core/skbuff.c:2636 eth_header+0x38/0x1f0 net/ethernet/eth.c:83 dev_hard_header include/linux/netdevice.h:3208 [inline] nf_send_reset6+0xce6/0x1270 net/ipv6/netfilter/nf_reject_ipv6.c:358 nft_reject_inet_eval+0x3b9/0x690 net/netfilter/nft_reject_inet.c:48 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_nf_pre_routing_ipv6+0x63e/0x770 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x9fd/0x1530 net/bridge/br_input.c:424 __netif_receive_skb_core+0x13e8/0x4570 net/core/dev.c:5562 __netif_receive_skb_one_core net/core/dev.c:5666 [inline] __netif_receive_skb+0x12f/0x650 net/core/dev.c:5781 netif_receive_skb_internal net/core/dev.c:5867 [inline] netif_receive_skb+0x1e8/0x890 net/core/dev.c:5926 tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1550 tun_get_user+0x3056/0x47e0 drivers/net/tun.c:2007 tun_chr_write_iter+0x10d/0x1f0 drivers/net/tun.c:2053 new_sync_write fs/read_write.c:590 [inline] vfs_write+0xa6d/0xc90 fs/read_write.c:683 ksys_write+0x183/0x2b0 fs/read_write.c:736 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdbeeb7d1ff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 8d 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 1c 8e 02 00 48 RSP: 002b:00007fdbee5ff000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fdbeed36058 RCX: 00007fdbeeb7d1ff RDX: 000000000000008e RSI: 0000000020000040 RDI: 00000000000000c8 RBP: 00007fdbeebf12be R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000008e R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fdbeed36058 R15: 00007ffc38de06e8 </TASK> Fixes: c8d7b98bec43 ("netfilter: move nf_send_resetX() code to nf_reject_ipvX modules") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-10-30netfilter: Fix use-after-free in get_info()Dong Chenchen
ip6table_nat module unload has refcnt warning for UAF. call trace is: WARNING: CPU: 1 PID: 379 at kernel/module/main.c:853 module_put+0x6f/0x80 Modules linked in: ip6table_nat(-) CPU: 1 UID: 0 PID: 379 Comm: ip6tables Not tainted 6.12.0-rc4-00047-gc2ee9f594da8-dirty #205 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:module_put+0x6f/0x80 Call Trace: <TASK> get_info+0x128/0x180 do_ip6t_get_ctl+0x6a/0x430 nf_getsockopt+0x46/0x80 ipv6_getsockopt+0xb9/0x100 rawv6_getsockopt+0x42/0x190 do_sock_getsockopt+0xaa/0x180 __sys_getsockopt+0x70/0xc0 __x64_sys_getsockopt+0x20/0x30 do_syscall_64+0xa2/0x1a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Concurrent execution of module unload and get_info() trigered the warning. The root cause is as follows: cpu0 cpu1 module_exit //mod->state = MODULE_STATE_GOING ip6table_nat_exit xt_unregister_template kfree(t) //removed from templ_list getinfo() t = xt_find_table_lock list_for_each_entry(tmpl, &xt_templates[af]...) if (strcmp(tmpl->name, name)) continue; //table not found try_module_get list_for_each_entry(t, &xt_net->tables[af]...) return t; //not get refcnt module_put(t->me) //uaf unregister_pernet_subsys //remove table from xt_net list While xt_table module was going away and has been removed from xt_templates list, we couldnt get refcnt of xt_table->me. Check module in xt_net->tables list re-traversal to fix it. Fixes: fdacd57c79b7 ("netfilter: x_tables: never register tables by default") Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-10-30selftests: netfilter: remove unused parameterLiu Jing
err is never used, remove it. Signed-off-by: Liu Jing <liujing@cmss.chinamobile.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-10-30xfs: streamline xfs_filestream_pick_agChristoph Hellwig
Directly return the error from xfs_bmap_longest_free_extent instead of breaking from the loop and handling it there, and use a done label to directly jump to the exist when we found a suitable perag structure to reduce the indentation level and pag/max_pag check complexity in the tail of the function. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2024-10-30xfs: fix finding a last resort AG in xfs_filestream_pick_agChristoph Hellwig
When the main loop in xfs_filestream_pick_ag fails to find a suitable AG it tries to just pick the online AG. But the loop for that uses args->pag as loop iterator while the later code expects pag to be set. Fix this by reusing the max_pag case for this last resort, and also add a check for impossible case of no AG just to make sure that the uninitialized pag doesn't even escape in theory. Reported-by: syzbot+4125a3c514e3436a02e6@syzkaller.appspotmail.com Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: syzbot+4125a3c514e3436a02e6@syzkaller.appspotmail.com Fixes: f8f1ed1ab3baba ("xfs: return a referenced perag from filestreams allocator") Cc: <stable@vger.kernel.org> # v6.3 Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2024-10-30xfs: Reduce unnecessary searches when searching for the best extentsChi Zhiling
Recently, we found that the CPU spent a lot of time in xfs_alloc_ag_vextent_size when the filesystem has millions of fragmented spaces. The reason is that we conducted much extra searching for extents that could not yield a better result, and these searches would cost a lot of time when there were millions of extents to search through. Even if we get the same result length, we don't switch our choice to the new one, so we can definitely terminate the search early. Since the result length cannot exceed the found length, when the found length equals the best result length we already have, we can conclude the search. We did a test in that filesystem: [root@localhost ~]# xfs_db -c freesp /dev/vdb from to extents blocks pct 1 1 215 215 0.01 2 3 994476 1988952 99.99 Before this patch: 0) | xfs_alloc_ag_vextent_size [xfs]() { 0) * 15597.94 us | } After this patch: 0) | xfs_alloc_ag_vextent_size [xfs]() { 0) 19.176 us | } Signed-off-by: Chi Zhiling <chizhiling@kylinos.cn> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2024-10-30xfs: Check for delayed allocations before setting extsizeOjaswin Mujoo
Extsize should only be allowed to be set on files with no data in it. For this, we check if the files have extents but miss to check if delayed extents are present. This patch adds that check. While we are at it, also refactor this check into a helper since it's used in some other places as well like xfs_inactive() or xfs_ioctl_setattr_xflags() **Without the patch (SUCCEEDS)** $ xfs_io -c 'open -f testfile' -c 'pwrite 0 1024' -c 'extsize 65536' wrote 1024/1024 bytes at offset 0 1 KiB, 1 ops; 0.0002 sec (4.628 MiB/sec and 4739.3365 ops/sec) **With the patch (FAILS as expected)** $ xfs_io -c 'open -f testfile' -c 'pwrite 0 1024' -c 'extsize 65536' wrote 1024/1024 bytes at offset 0 1 KiB, 1 ops; 0.0002 sec (4.628 MiB/sec and 4739.3365 ops/sec) xfs_io: FS_IOC_FSSETXATTR testfile: Invalid argument Fixes: e94af02a9cd7 ("[XFS] fix old xfs_setattr mis-merge from irix; mostly harmless esp if not using xfs rt") Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: John Garry <john.g.garry@oracle.com> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2024-10-30accel/ivpu: Fix NOC firewall interrupt handlingAndrzej Kacprowski
The NOC firewall interrupt means that the HW prevented unauthorized access to a protected resource, so there is no need to trigger device reset in such case. To facilitate security testing add firewall_irq_counter debugfs file that tracks firewall interrupts. Fixes: 8a27ad81f7d3 ("accel/ivpu: Split IP and buttress code") Cc: stable@vger.kernel.org # v6.11+ Signed-off-by: Andrzej Kacprowski <Andrzej.Kacprowski@intel.com> Reviewed-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com> Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com> Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241017144958.79327-1-jacek.lawrynowicz@linux.intel.com
2024-10-30selftests: add file SLAB_TYPESAFE_BY_RCU recycling stressorChristian Brauner
Add a simple file stressor that lives directly in-tree. This will create a bunch of processes that each open 500 file descriptors and then use close_range() to close them all. Concurrently, other processes read /proc/<pid>/fd/ which rougly does f = fget_task_next(p, &fd); if (!f) break; data.mode = f->f_mode; fput(f); Which means that it'll try to get a reference to a file in another task's file descriptor table. Under heavy file load it is increasingly likely that the other task will manage to close @file and @file will be recycled due to SLAB_TYPEAFE_BY_RCU concurrently. This will trigger various warnings in the file reference counting code. Link: https://lore.kernel.org/r/20241021-vergab-streuen-924df15dceb9@brauner Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-30Merge branch 'work.fdtable' into vfs.fileChristian Brauner
Bring in the fdtable changes for this cycle. Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-30Merge patch series "fs: introduce file_ref_t"Christian Brauner
Christian Brauner <brauner@kernel.org> says: As atomic_inc_not_zero() is implemented with a try_cmpxchg() loop it has O(N^2) behaviour under contention with N concurrent operations and it is in a hot path in __fget_files_rcu(). The rcuref infrastructures remedies this problem by using an unconditional increment relying on safe- and dead zones to make this work and requiring rcu protection for the data structure in question. This not just scales better it also introduces overflow protection. However, in contrast to generic rcuref, files require a memory barrier and thus cannot rely on *_relaxed() atomic operations and also require to be built on atomic_long_t as having massive amounts of reference isn't unheard of even if it is just an attack. As suggested by Linus, add a file specific variant instead of making this a generic library. I've been testing this with will-it-scale using a multi-threaded fstat() on the same file descriptor on a machine that Jens gave me access (thank you very much!): processor : 511 vendor_id : AuthenticAMD cpu family : 25 model : 160 model name : AMD EPYC 9754 128-Core Processor and I consistently get a 3-5% improvement on workloads with 256+ and more threads comparing v6.12-rc1 as base with and without these patches applied. * patches from https://lore.kernel.org/r/20241007-brauner-file-rcuref-v2-0-387e24dc9163@kernel.org: fs: port files to file_ref fs: add file_ref fs: protect backing files with rcu Link: https://lore.kernel.org/r/20241007-brauner-file-rcuref-v2-0-387e24dc9163@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-30fs: port files to file_refChristian Brauner
Port files to rely on file_ref reference to improve scaling and gain overflow protection. - We continue to WARN during get_file() in case a file that is already marked dead is revived as get_file() is only valid if the caller already holds a reference to the file. This hasn't changed just the check changes. - The semantics for epoll and ttm's dmabuf usage have changed. Both epoll and ttm synchronize with __fput() to prevent the underlying file from beeing freed. (1) epoll Explaining epoll is straightforward using a simple diagram. Essentially, the mutex of the epoll instance needs to be taken in both __fput() and around epi_fget() preventing the file from being freed while it is polled or preventing the file from being resurrected. CPU1 CPU2 fput(file) -> __fput(file) -> eventpoll_release(file) -> eventpoll_release_file(file) mutex_lock(&ep->mtx) epi_item_poll() -> epi_fget() -> file_ref_get(file) mutex_unlock(&ep->mtx) mutex_lock(&ep->mtx); __ep_remove() mutex_unlock(&ep->mtx); -> kmem_cache_free(file) (2) ttm dmabuf This explanation is a bit more involved. A regular dmabuf file stashed the dmabuf in file->private_data and the file in dmabuf->file: file->private_data = dmabuf; dmabuf->file = file; The generic release method of a dmabuf file handles file specific things: f_op->release::dma_buf_file_release() while the generic dentry release method of a dmabuf handles dmabuf freeing including driver specific things: dentry->d_release::dma_buf_release() During ttm dmabuf initialization in ttm_object_device_init() the ttm driver copies the provided struct dma_buf_ops into a private location: struct ttm_object_device { spinlock_t object_lock; struct dma_buf_ops ops; void (*dmabuf_release)(struct dma_buf *dma_buf); struct idr idr; }; ttm_object_device_init(const struct dma_buf_ops *ops) { // copy original dma_buf_ops in private location tdev->ops = *ops; // stash the release method of the original struct dma_buf_ops tdev->dmabuf_release = tdev->ops.release; // override the release method in the copy of the struct dma_buf_ops // with ttm's own dmabuf release method tdev->ops.release = ttm_prime_dmabuf_release; } When a new dmabuf is created the struct dma_buf_ops with the overriden release method set to ttm_prime_dmabuf_release is passed in exp_info.ops: DEFINE_DMA_BUF_EXPORT_INFO(exp_info); exp_info.ops = &tdev->ops; exp_info.size = prime->size; exp_info.flags = flags; exp_info.priv = prime; The call to dma_buf_export() then sets mutex_lock_interruptible(&prime->mutex); dma_buf = dma_buf_export(&exp_info) { dmabuf->ops = exp_info->ops; } mutex_unlock(&prime->mutex); which creates a new dmabuf file and then install a file descriptor to it in the callers file descriptor table: ret = dma_buf_fd(dma_buf, flags); When that dmabuf file is closed we now get: fput(file) -> __fput(file) -> f_op->release::dma_buf_file_release() -> dput() -> d_op->d_release::dma_buf_release() -> dmabuf->ops->release::ttm_prime_dmabuf_release() mutex_lock(&prime->mutex); if (prime->dma_buf == dma_buf) prime->dma_buf = NULL; mutex_unlock(&prime->mutex); Where we can see that prime->dma_buf is set to NULL. So when we have the following diagram: CPU1 CPU2 fput(file) -> __fput(file) -> f_op->release::dma_buf_file_release() -> dput() -> d_op->d_release::dma_buf_release() -> dmabuf->ops->release::ttm_prime_dmabuf_release() ttm_prime_handle_to_fd() mutex_lock_interruptible(&prime->mutex) dma_buf = prime->dma_buf dma_buf && get_dma_buf_unless_doomed(dma_buf) -> file_ref_get(dma_buf->file) mutex_unlock(&prime->mutex); mutex_lock(&prime->mutex); if (prime->dma_buf == dma_buf) prime->dma_buf = NULL; mutex_unlock(&prime->mutex); -> kmem_cache_free(file) The logic of the mechanism is the same as for epoll: sync with __fput() preventing the file from being freed. Here the synchronization happens through the ttm instance's prime->mutex. Basically, the lifetime of the dma_buf and the file are tighly coupled. Both (1) and (2) used to call atomic_inc_not_zero() to check whether the file has already been marked dead and then refuse to revive it. This is only safe because both (1) and (2) sync with __fput() and thus prevent kmem_cache_free() on the file being called and thus prevent the file from being immediately recycled due to SLAB_TYPESAFE_BY_RCU. Both (1) and (2) have been ported from atomic_inc_not_zero() to file_ref_get(). That means a file that is already in the process of being marked as FILE_REF_DEAD: file_ref_put() cnt = atomic_long_dec_return() -> __file_ref_put(cnt) if (cnt == FIlE_REF_NOREF) atomic_long_try_cmpxchg_release(cnt, FILE_REF_DEAD) can be revived again: CPU1 CPU2 file_ref_put() cnt = atomic_long_dec_return() -> __file_ref_put(cnt) if (cnt == FIlE_REF_NOREF) file_ref_get() // Brings reference back to FILE_REF_ONEREF atomic_long_add_negative() atomic_long_try_cmpxchg_release(cnt, FILE_REF_DEAD) This is fine and inherent to the file_ref_get()/file_ref_put() semantics. For both (1) and (2) this is safe because __fput() is prevented from making progress if file_ref_get() fails due to the aforementioned synchronization mechanisms. Two cases need to be considered that affect both (1) epoll and (2) ttm dmabuf: (i) fput()'s file_ref_put() and marks the file as FILE_REF_NOREF but before that fput() can mark the file as FILE_REF_DEAD someone manages to sneak in a file_ref_get() and brings the refcount back from FILE_REF_NOREF to FILE_REF_ONEREF. In that case the original fput() doesn't call __fput(). For epoll the poll will finish and for ttm dmabuf the file can be used again. For ttm dambuf this is actually an advantage because it avoids immediately allocating a new dmabuf object. CPU1 CPU2 file_ref_put() cnt = atomic_long_dec_return() -> __file_ref_put(cnt) if (cnt == FIlE_REF_NOREF) file_ref_get() // Brings reference back to FILE_REF_ONEREF atomic_long_add_negative() atomic_long_try_cmpxchg_release(cnt, FILE_REF_DEAD) (ii) fput()'s file_ref_put() marks the file FILE_REF_NOREF and also suceeds in actually marking it FILE_REF_DEAD and then calls into __fput() to free the file. When either (1) or (2) call file_ref_get() they fail as atomic_long_add_negative() will return true. At the same time, both (1) and (2) all file_ref_get() under mutexes that __fput() must also acquire preventing kmem_cache_free() from freeing the file. So while this might be treated as a change in semantics for (1) and (2) it really isn't. It if should end up causing issues this can be fixed by adding a helper that does something like: long cnt = atomic_long_read(&ref->refcnt); do { if (cnt < 0) return false; } while (!atomic_long_try_cmpxchg(&ref->refcnt, &cnt, cnt + 1)); return true; which would block FILE_REF_NOREF to FILE_REF_ONEREF transitions. - Jann correctly pointed out that kmem_cache_zalloc() cannot be used anymore once files have been ported to file_ref_t. The kmem_cache_zalloc() call will memset() the whole struct file to zero when it is reallocated. This will also set file->f_ref to zero which mens that a concurrent file_ref_get() can return true: CPU1 CPU2 __get_file_rcu() rcu_dereference_raw() close() [frees file] alloc_empty_file() kmem_cache_zalloc() [reallocates same file] memset(..., 0, ...) file_ref_get() [increments 0->1, returns true] init_file() file_ref_init(..., 1) [sets to 0] rcu_dereference_raw() fput() file_ref_put() [decrements 0->FILE_REF_NOREF, frees file] [UAF] causing a concurrent __get_file_rcu() call to acquire a reference to the file that is about to be reallocated and immediately freeing it on realizing that it has been recycled. This causes a UAF for the task that reallocated/recycled the file. This is prevented by switching from kmem_cache_zalloc() to kmem_cache_alloc() and initializing the fields manually. With file->f_ref initialized last. Note that a memset() also isn't guaranteed to atomically update an unsigned long so it's theoretically possible to see torn and therefore bogus counter values. Link: https://lore.kernel.org/r/20241007-brauner-file-rcuref-v2-3-387e24dc9163@kernel.org Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-29bpf: disallow 40-bytes extra stack for bpf_fastcall patternsEduard Zingerman
Hou Tao reported an issue with bpf_fastcall patterns allowing extra stack space above MAX_BPF_STACK limit. This extra stack allowance is not integrated properly with the following verifier parts: - backtracking logic still assumes that stack can't exceed MAX_BPF_STACK; - bpf_verifier_env->scratched_stack_slots assumes only 64 slots are available. Here is an example of an issue with precision tracking (note stack slot -8 tracked as precise instead of -520): 0: (b7) r1 = 42 ; R1_w=42 1: (b7) r2 = 42 ; R2_w=42 2: (7b) *(u64 *)(r10 -512) = r1 ; R1_w=42 R10=fp0 fp-512_w=42 3: (7b) *(u64 *)(r10 -520) = r2 ; R2_w=42 R10=fp0 fp-520_w=42 4: (85) call bpf_get_smp_processor_id#8 ; R0_w=scalar(...) 5: (79) r2 = *(u64 *)(r10 -520) ; R2_w=42 R10=fp0 fp-520_w=42 6: (79) r1 = *(u64 *)(r10 -512) ; R1_w=42 R10=fp0 fp-512_w=42 7: (bf) r3 = r10 ; R3_w=fp0 R10=fp0 8: (0f) r3 += r2 mark_precise: frame0: last_idx 8 first_idx 0 subseq_idx -1 mark_precise: frame0: regs=r2 stack= before 7: (bf) r3 = r10 mark_precise: frame0: regs=r2 stack= before 6: (79) r1 = *(u64 *)(r10 -512) mark_precise: frame0: regs=r2 stack= before 5: (79) r2 = *(u64 *)(r10 -520) mark_precise: frame0: regs= stack=-8 before 4: (85) call bpf_get_smp_processor_id#8 mark_precise: frame0: regs= stack=-8 before 3: (7b) *(u64 *)(r10 -520) = r2 mark_precise: frame0: regs=r2 stack= before 2: (7b) *(u64 *)(r10 -512) = r1 mark_precise: frame0: regs=r2 stack= before 1: (b7) r2 = 42 9: R2_w=42 R3_w=fp42 9: (95) exit This patch disables the additional allowance for the moment. Also, two test cases are removed: - bpf_fastcall_max_stack_ok: it fails w/o additional stack allowance; - bpf_fastcall_max_stack_fail: this test is no longer necessary, stack size follows regular rules, pattern invalidation is checked by other test cases. Reported-by: Hou Tao <houtao@huaweicloud.com> Closes: https://lore.kernel.org/bpf/20241023022752.172005-1-houtao@huaweicloud.com/ Fixes: 5b5f51bff1b6 ("bpf: no_caller_saved_registers attribute for helper calls") Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Tested-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20241029193911.1575719-1-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-29Merge tag 'cgroup-for-6.12-rc5-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: - cgroup_bpf_release_fn() could saturate system_wq with cgrp->bpf.release_work which can then form a circular dependency leading to deadlocks. Fix by using a dedicated workqueue. The system_wq's max concurrency limit is being increased separately. - Fix theoretical off-by-one bug when enforcing max cgroup hierarchy depth * tag 'cgroup-for-6.12-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: Fix potential overflow issue when checking max_depth cgroup/bpf: use a dedicated workqueue for cgroup bpf destruction
2024-10-29Merge tag 'sched_ext-for-6.12-rc5-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext Pull sched_ext fixes from Tejun Heo: - Instances of scx_ops_bypass() could race each other leading to misbehavior. Fix by protecting the operation with a spinlock. - selftest and userspace header fixes * tag 'sched_ext-for-6.12-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: sched_ext: Fix enq_last_no_enq_fails selftest sched_ext: Make cast_mask() inline scx: Fix raciness in scx_ops_bypass() scx: Fix exit selftest to use custom DSQ sched_ext: Fix function pointer type mismatches in BPF selftests selftests/sched_ext: add order-only dependency of runner.o on BPFOBJ
2024-10-29Merge tag 'slab-for-6.12-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab fixes from Vlastimil Babka: - Fix for a slub_kunit test warning with MEM_ALLOC_PROFILING_DEBUG (Pei Xiao) - Fix for a MTE-based KASAN BUG in krealloc() (Qun-Wei Lin) * tag 'slab-for-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: mm: krealloc: Fix MTE false alarm in __do_krealloc slub/kunit: fix a WARNING due to unwrapped __kmalloc_cache_noprof
2024-10-29Merge tag 'mm-hotfixes-stable-2024-10-28-21-50' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "21 hotfixes. 13 are cc:stable. 13 are MM and 8 are non-MM. No particular theme here - mainly singletons, a couple of doubletons. Please see the changelogs" * tag 'mm-hotfixes-stable-2024-10-28-21-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (21 commits) mm: avoid unconditional one-tick sleep when swapcache_prepare fails mseal: update mseal.rst mm: split critical region in remap_file_pages() and invoke LSMs in between selftests/mm: fix deadlock for fork after pthread_create with atomic_bool Revert "selftests/mm: replace atomic_bool with pthread_barrier_t" Revert "selftests/mm: fix deadlock for fork after pthread_create on ARM" tools: testing: add expand-only mode VMA test mm/vma: add expand-only VMA merge mode and optimise do_brk_flags() resource,kexec: walk_system_ram_res_rev must retain resource flags nilfs2: fix kernel bug due to missing clearing of checked flag mm: numa_clear_kernel_node_hotplug: Add NUMA_NO_NODE check for node id ocfs2: pass u64 to ocfs2_truncate_inline maybe overflow mm: shmem: fix data-race in shmem_getattr() mm: mark mas allocation in vms_abort_munmap_vmas as __GFP_NOFAIL x86/traps: move kmsan check after instrumentation_begin resource: remove dependency on SPARSEMEM from GET_FREE_REGION mm/mmap: fix race in mmap_region() with ftruncate() mm/page_alloc: let GFP_ATOMIC order-0 allocs access highatomic reserves fork: only invoke khugepaged, ksm hooks if no error fork: do not invoke uffd on fork if error occurs ...
2024-10-29Merge tag 'tpmdd-next-6.12-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd Pull tpm fix from Jarkko Sakkinen: "Address a significant boot-time delay issue" Link: https://bugzilla.kernel.org/show_bug.cgi?id=219229 * tag 'tpmdd-next-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd: tpm: Lazily flush the auth session tpm: Rollback tpm2_load_null() tpm: Return tpm2_sessions_init() when null key creation fails
2024-10-29Merge tag 'wireless-2024-10-29' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless Johannes Berg says: ==================== wireless fixes for v6.12-rc6 Another set of fixes, mostly iwlwifi: * fix infinite loop in 6 GHz scan if more than 255 colocated APs were reported * revert removal of retry loops for now to work around issues with firmware initialization on some devices/platforms * fix SAR table issues with some BIOSes * fix race in suspend/debug collection * fix memory leak in fw recovery * fix link ID leak in AP mode for older devices * fix sending TX power constraints * fix link handling in FW restart And also the stack: * fix setting TX power from userspace with the new chanctx emulation code for old-style drivers * fix a memory corruption bug due to structure embedding * fix CQM configuration double-free when moving between net namespaces * tag 'wireless-2024-10-29' of https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless: wifi: mac80211: ieee80211_i: Fix memory corruption bug in struct ieee80211_chanctx wifi: iwlwifi: mvm: fix 6 GHz scan construction wifi: cfg80211: clear wdev->cqm_config pointer on free mac80211: fix user-power when emulating chanctx Revert "wifi: iwlwifi: remove retry loops in start" wifi: iwlwifi: mvm: don't add default link in fw restart flow wifi: iwlwifi: mvm: Fix response handling in iwl_mvm_send_recovery_cmd() wifi: iwlwifi: mvm: SAR table alignment wifi: iwlwifi: mvm: Use the sync timepoint API in suspend wifi: iwlwifi: mvm: really send iwl_txpower_constraints_cmd wifi: iwlwifi: mvm: don't leak a link on AP removal ==================== Link: https://patch.msgid.link/20241029093926.13750-3-johannes@sipsolutions.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-29net: fix crash when config small gso_max_size/gso_ipv4_max_sizeWang Liang
Config a small gso_max_size/gso_ipv4_max_size will lead to an underflow in sk_dst_gso_max_size(), which may trigger a BUG_ON crash, because sk->sk_gso_max_size would be much bigger than device limits. Call Trace: tcp_write_xmit tso_segs = tcp_init_tso_segs(skb, mss_now); tcp_set_skb_tso_segs tcp_skb_pcount_set // skb->len = 524288, mss_now = 8 // u16 tso_segs = 524288/8 = 65535 -> 0 tso_segs = DIV_ROUND_UP(skb->len, mss_now) BUG_ON(!tso_segs) Add check for the minimum value of gso_max_size and gso_ipv4_max_size. Fixes: 46e6b992c250 ("rtnetlink: allow GSO maximums to be set on device creation") Fixes: 9eefedd58ae1 ("net: add gso_ipv4_max_size and gro_ipv4_max_size per device") Signed-off-by: Wang Liang <wangliang74@huawei.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20241023035213.517386-1-wangliang74@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-29btrfs: fix use-after-free of block device file in __btrfs_free_extra_devids()Zhihao Cheng
Mounting btrfs from two images (which have the same one fsid and two different dev_uuids) in certain executing order may trigger an UAF for variable 'device->bdev_file' in __btrfs_free_extra_devids(). And following are the details: 1. Attach image_1 to loop0, attach image_2 to loop1, and scan btrfs devices by ioctl(BTRFS_IOC_SCAN_DEV): / btrfs_device_1 → loop0 fs_device \ btrfs_device_2 → loop1 2. mount /dev/loop0 /mnt btrfs_open_devices btrfs_device_1->bdev_file = btrfs_get_bdev_and_sb(loop0) btrfs_device_2->bdev_file = btrfs_get_bdev_and_sb(loop1) btrfs_fill_super open_ctree fail: btrfs_close_devices // -ENOMEM btrfs_close_bdev(btrfs_device_1) fput(btrfs_device_1->bdev_file) // btrfs_device_1->bdev_file is freed btrfs_close_bdev(btrfs_device_2) fput(btrfs_device_2->bdev_file) 3. mount /dev/loop1 /mnt btrfs_open_devices btrfs_get_bdev_and_sb(&bdev_file) // EIO, btrfs_device_1->bdev_file is not assigned, // which points to a freed memory area btrfs_device_2->bdev_file = btrfs_get_bdev_and_sb(loop1) btrfs_fill_super open_ctree btrfs_free_extra_devids if (btrfs_device_1->bdev_file) fput(btrfs_device_1->bdev_file) // UAF ! Fix it by setting 'device->bdev_file' as 'NULL' after closing the btrfs_device in btrfs_close_one_device(). Fixes: 142388194191 ("btrfs: do not background blkdev_put()") CC: stable@vger.kernel.org # 4.19+ Link: https://bugzilla.kernel.org/show_bug.cgi?id=219408 Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2024-10-29selftests/bpf: Add test for trie_get_next_key()Byeonguk Jeong
Add a test for out-of-bounds write in trie_get_next_key() when a full path from root to leaf exists and bpf_map_get_next_key() is called with the leaf node. It may crashes the kernel on failure, so please run in a VM. Signed-off-by: Byeonguk Jeong <jungbu2855@gmail.com> Acked-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/Zxx4ep78tsbeWPVM@localhost.localdomain Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-29bpf: Fix out-of-bounds write in trie_get_next_key()Byeonguk Jeong
trie_get_next_key() allocates a node stack with size trie->max_prefixlen, while it writes (trie->max_prefixlen + 1) nodes to the stack when it has full paths from the root to leaves. For example, consider a trie with max_prefixlen is 8, and the nodes with key 0x00/0, 0x00/1, 0x00/2, ... 0x00/8 inserted. Subsequent calls to trie_get_next_key with _key with .prefixlen = 8 make 9 nodes be written on the node stack with size 8. Fixes: b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE map") Signed-off-by: Byeonguk Jeong <jungbu2855@gmail.com> Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org> Tested-by: Hou Tao <houtao1@huawei.com> Acked-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/Zxx384ZfdlFYnz6J@localhost.localdomain Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-10-29io_uring/rsrc: kill io_charge_rsrc_node()Jens Axboe
It's only used from __io_req_set_rsrc_node(), and it takes both the ctx and node itself, while never using the ctx. Just open-code the basic refs++ in __io_req_set_rsrc_node() instead. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring/splice: open code 2nd direct file assignmentJens Axboe
In preparation for not pinning the whole registered file table, open code the second potential direct file assignment. This will be handled by appropriate helpers in the future, for now just do it manually. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring: specify freeptr usage for SLAB_TYPESAFE_BY_RCU io_kiocb cacheJens Axboe
Doesn't matter right now as there's still some bytes left for it, but let's prepare for the io_kiocb potentially growing and add a specific freeptr offset for it. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring/rsrc: move struct io_fixed_file to rsrc.h headerJens Axboe
There's no need for this internal structure to be visible, move it to the private rsrc.h header instead. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring/nop: add support for testing registered files and buffersJens Axboe
Useful for testing performance/efficiency impact of registered files and buffers, vs (particularly) non-registered files. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring: add support for fixed wait regionsJens Axboe
Generally applications have 1 or a few waits of waiting, yet they pass in a struct io_uring_getevents_arg every time. This needs to get copied and, in turn, the timeout value needs to get copied. Rather than do this for every invocation, allow the application to register a fixed set of wait regions that can simply be indexed when asking the kernel to wait on events. At ring setup time, the application can register a number of these wait regions and initialize region/index 0 upfront: struct io_uring_reg_wait *reg; reg = io_uring_setup_reg_wait(ring, nr_regions, &ret); /* set timeout and mark as set, sigmask/sigmask_sz as needed */ reg->ts.tv_sec = 0; reg->ts.tv_nsec = 100000; reg->flags = IORING_REG_WAIT_TS; where nr_regions >= 1 && nr_regions <= PAGE_SIZE / sizeof(*reg). The above initializes index 0, but 63 other regions can be initialized, if needed. Now, instead of doing: struct __kernel_timespec timeout = { .tv_nsec = 100000, }; io_uring_submit_and_wait_timeout(ring, &cqe, nr, &t, NULL); to wait for events for each submit_and_wait, or just wait, operation, it can just reference the above region at offset 0 and do: io_uring_submit_and_wait_reg(ring, &cqe, nr, 0); to achieve the same goal of waiting 100usec without needing to copy both struct io_uring_getevents_arg (24b) and struct __kernel_timeout (16b) for each invocation. Struct io_uring_reg_wait looks as follows: struct io_uring_reg_wait { struct __kernel_timespec ts; __u32 min_wait_usec; __u32 flags; __u64 sigmask; __u32 sigmask_sz; __u32 pad[3]; __u64 pad2[2]; }; embedding the timeout itself in the region, rather than passing it as a pointer as well. Note that the signal mask is still passed as a pointer, both for compatability reasons, but also because there doesn't seem to be a lot of high frequency waits scenarios that involve setting and resetting the signal mask for each wait. The application is free to modify any region before a wait call, or it can use keep multiple regions with different settings to avoid needing to modify the same one for wait calls. Up to a page size of regions is mapped by default, allowing PAGE_SIZE / 64 available regions for use. The registered region must fit within a page. On a 4kb page size system, that allows for 64 wait regions if a full page is used, as the size of struct io_uring_reg_wait is 64b. The region registered must be aligned to io_uring_reg_wait in size. It's valid to register less than 64 entries. In network performance testing with zero-copy, this reduced the time spent waiting on the TX side from 3.12% to 0.3% and the RX side from 4.4% to 0.3%. Wait regions are fixed for the lifetime of the ring - once registered, they are persistent until the ring is torn down. The regions support minimum wait timeout as well as the regular waits. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring: change io_get_ext_arg() to use uaccess begin + endJens Axboe
In scenarios where a high frequency of wait events are seen, the copy of the struct io_uring_getevents_arg is quite noticeable in the profiles in terms of time spent. It can be seen as up to 3.5-4.5%. Rewrite the copy-in logic, saving about 0.5% of the time. Reviewed-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring: switch struct ext_arg from __kernel_timespec to timespec64Jens Axboe
This avoids intermediate storage for turning a __kernel_timespec user pointer into an on-stack struct timespec64, only then to turn it into a ktime_t. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring/sqpoll: wait on sqd->wait for thread parkingJens Axboe
io_sqd_handle_event() just does a mutex unlock/lock dance when it's supposed to park, somewhat relying on full ordering with the thread trying to park it which does a similar unlock/lock dance on sqd->lock. However, with adaptive spinning on mutexes, this can waste an awful lot of time. Normally this isn't very noticeable, as parking and unparking the thread isn't a common (or fast path) occurence. However, in testing ring resizing, it's testing exactly that, as each resize will require the SQPOLL to safely park and unpark. Have io_sq_thread_park() explicitly wait on sqd->park_pending being zero before attempting to grab the sqd->lock again. In a resize test, this brings the runtime of SQPOLL down from about 60 seconds to a few seconds, just like the !SQPOLL tests. And saves a ton of spinning time on the mutex, on both sides. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring/register: add IORING_REGISTER_RESIZE_RINGSJens Axboe
Once a ring has been created, the size of the CQ and SQ rings are fixed. Usually this isn't a problem on the SQ ring side, as it merely controls the available number of requests that can be submitted in a single system call, and there's rarely a need to change that. For the CQ ring, it's a different story. For most efficient use of io_uring, it's important that the CQ ring never overflows. This means that applications must size it for the worst case scenario, which can be wasteful. Add IORING_REGISTER_RESIZE_RINGS, which allows an application to resize the existing rings. It takes a struct io_uring_params argument, the same one which is used to setup the ring initially, and resizes rings according to the sizes given. Certain properties are always inherited from the original ring setup, like SQE128/CQE32 and other setup options. The implementation only allows flag associated with how the CQ ring is sized and clamped. Existing unconsumed SQE and CQE entries are copied as part of the process. If either the SQ or CQ resized destination ring cannot hold the entries already present in the source rings, then the operation is failed with -EOVERFLOW. Any register op holds ->uring_lock, which prevents new submissions, and the internal mapping holds the completion lock as well across moving CQ ring state. To prevent races between mmap and ring resizing, add a mutex that's solely used to serialize ring resize and mmap. mmap_sem can't be used here, as as fork'ed process may be doing mmaps on the ring as well. The ctx->resize_lock is held across mmap operations, and the resize will grab it before swapping out the already mapped new data. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring/memmap: explicitly return -EFAULT for mmap on NULL ringsJens Axboe
The later mapping will actually check this too, but in terms of code clarify, explicitly check for whether or not the rings and sqes are valid during validation. That makes it explicit that if they are non-NULL, they are valid and can get mapped. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring: abstract out a bit of the ring filling logicJens Axboe
Abstract out a io_uring_fill_params() helper, which fills out the necessary bits of struct io_uring_params. Add it to io_uring.h as well, in preparation for having another internal user of it. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring: move max entry definition and ring sizing into headerJens Axboe
In preparation for needing this somewhere else, move the definitions for the maximum CQ and SQ ring size into io_uring.h. Make the rings_size() helper available as well, and have it take just the setup flags argument rather than the fill ring pointer. That's all that is needed. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring/net: clean up io_msg_copy_hdrPavel Begunkov
Put sr->umsg into a local variable, so it doesn't repeat "sr->umsg->" for every field. It looks nicer, and likely without the patch it compiles into a bunch of umsg memory reads. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/26c2f30b491ea7998bfdb5bb290662572a61064d.1729607201.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring/net: don't alias send user pointer readsPavel Begunkov
We keep user pointers in an union, which could be a user buffer or a user pointer to msghdr. What is confusing is that it potenitally reads and assigns sqe->addr as one type but then uses it as another via the union. Even more, it's not even consistent across copy and zerocopy versions. Make send and sendmsg setup helpers read sqe->addr and treat it as the right type from the beginning. The end goal would be to get rid of the use of struct io_sr_msg::umsg for send requests as we only need it at the prep side. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/685d788605f5d78af18802fcabf61ba65cfd8002.1729607201.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring/net: don't store send address ptrPavel Begunkov
For non "msg" requests we copy the address at the prep stage and there is no need to store the address user pointer long term. Pass the SQE into io_send_setup(), let it parse it, and remove struct io_sr_msg addr addr_len fields. It saves some space and also less confusing. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/db3dce544e17ca9d4b17d2506fbbac1da8a87824.1729607201.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring/net: split send and sendmsg prep helpersPavel Begunkov
A preparation patch splitting io_sendmsg_prep_setup into two separate helpers for send and sendmsg variants. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/1a2319471ba040e053b7f1d22f4af510d1118eca.1729607201.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-10-29io_uring: kill 'imu' from struct io_kiocbJens Axboe
It's no longer being used, remove it. Signed-off-by: Jens Axboe <axboe@kernel.dk>