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2025-03-10Merge afs RCU pathwalk fixChristian Brauner
Bring in the fix for afs_atcell_get_link() to handle RCU pathwalk from the afs branch for this cycle. This fix has to go upstream now. Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-10afs: Fix afs_atcell_get_link() to handle RCU pathwalkDavid Howells
The ->get_link() method may be entered under RCU pathwalk conditions (in which case, the dentry pointer is NULL). This is not taken account of by afs_atcell_get_link() and lockdep will complain when it tries to lock an rwsem. Fix this by marking net->ws_cell as __rcu and using RCU access macros on it and by making afs_atcell_get_link() just return a pointer to the name in RCU pathwalk without taking net->cells_lock or a ref on the cell as RCU will protect the name storage (the cell is already freed via call_rcu()). Fixes: 30bca65bbbae ("afs: Make /afs/@cell and /afs/.@cell symlinks") Reported-by: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20250310094206.801057-2-dhowells@redhat.com/ # v4
2025-03-06fs/pipe: add simpler helpers for common casesLinus Torvalds
The fix to atomically read the pipe head and tail state when not holding the pipe mutex has caused a number of headaches due to the size change of the involved types. It turns out that we don't have _that_ many places that access these fields directly and were affected, but we have more than we strictly should have, because our low-level helper functions have been designed to have intimate knowledge of how the pipes work. And as a result, that random noise of direct 'pipe->head' and 'pipe->tail' accesses makes it harder to pinpoint any actual potential problem spots remaining. For example, we didn't have a "is the pipe full" helper function, but instead had a "given these pipe buffer indexes and this pipe size, is the pipe full". That's because some low-level pipe code does actually want that much more complicated interface. But most other places literally just want a "is the pipe full" helper, and not having it meant that those places ended up being unnecessarily much too aware of this all. It would have been much better if only the very core pipe code that cared had been the one aware of this all. So let's fix it - better late than never. This just introduces the trivial wrappers for "is this pipe full or empty" and to get how many pipe buffers are used, so that instead of writing if (pipe_full(pipe->head, pipe->tail, pipe->max_usage)) the places that literally just want to know if a pipe is full can just say if (pipe_is_full(pipe)) instead. The existing trivial cases were converted with a 'sed' script. This cuts down on the places that access pipe->head and pipe->tail directly outside of the pipe code (and core splice code) quite a lot. The splice code in particular still revels in doing the direct low-level accesses, and the fuse fuse_dev_splice_write() code also seems a bit unnecessarily eager to go very low-level, but it's at least a bit better than it used to be. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-03-06Merge tag 'drm-fixes-2025-03-07' of https://gitlab.freedesktop.org/drm/kernelLinus Torvalds
Pull drm fixes from Dave Airlie: "Fixes across the board, mostly xe and imagination with some amd and misc others. The xe fixes are mostly hmm related, though there are some others in there as well, nothing really stands out otherwise. The nouveau Kconfig to select FW_CACHE is in this, which we discussed a while back. nouveau: - rely on fw caching Kconfig fix imagination: - avoid deadlock on fence release - fix fence initialisation - fix timestamps firmware traces scheduler: - fix include guard bochs: - dpms fix i915: - bump max stream count to match pipes xe: - Remove double page flip on initial plane - Properly setup userptr pfn_flags_mask - Fix GT "for each engine" workarounds - Fix userptr races and missed validations - Userptr invalid page access fixes - Cleanup some style nits amdgpu: - Fix NULL check in DC code - SMU 14 fix amdkfd: - Fix NULL check in queue validation radeon: - RS400 HyperZ fix" * tag 'drm-fixes-2025-03-07' of https://gitlab.freedesktop.org/drm/kernel: (22 commits) drm/bochs: Fix DPMS regression drm/xe/userptr: Unmap userptrs in the mmu notifier drm/xe/hmm: Don't dereference struct page pointers without notifier lock drm/xe/hmm: Style- and include fixes drm/xe: Add staging tree for VM binds drm/xe: Fix fault mode invalidation with unbind drm/xe/vm: Fix a misplaced #endif drm/xe/vm: Validate userptr during gpu vma prefetching drm/amd/pm: always allow ih interrupt from fw drm/radeon: Fix rs400_gpu_init for ATI mobility radeon Xpress 200M drm/amdkfd: Fix NULL Pointer Dereference in KFD queue drm/amd/display: Fix null check for pipe_ctx->plane_state in resource_build_scaling_params drm/xe: Fix GT "for each engine" workarounds drm/xe/userptr: properly setup pfn_flags_mask drm/i915/mst: update max stream count to match number of pipes drm/xe: Remove double pageflip drm/sched: Fix preprocessor guard drm/imagination: Fix timestamps in firmware traces drm/imagination: only init job done fences once drm/imagination: Hold drm_gem_gpuva lock for unmap ...
2025-03-07Merge tag 'amd-drm-fixes-6.14-2025-03-06' of ↵Dave Airlie
https://gitlab.freedesktop.org/agd5f/linux into drm-fixes amd-drm-fixes-6.14-2025-03-06: amdgpu: - Fix NULL check in DC code - SMU 14 fix amdkfd: - Fix NULL check in queue validation radeon: - RS400 HyperZ fix Signed-off-by: Dave Airlie <airlied@redhat.com> From: Alex Deucher <alexander.deucher@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250306193424.27413-1-alexander.deucher@amd.com
2025-03-06Merge tag 'bcachefs-2025-03-06' of git://evilpiepirate.org/bcachefsLinus Torvalds
Pull bcachefs fixes from Kent Overstreet: - Fix a compatibility issue: we shouldn't be setting incompat feature bits unless explicitly requested - Fix another bug where the journal alloc/resize path could spuriously fail with -BCH_ERR_open_buckets_empty - Copygc shouldn't run on read-only devices: fragmentation isn't an issue if we're not currently writing to a given device, and it may not have anywhere to move the data to * tag 'bcachefs-2025-03-06' of git://evilpiepirate.org/bcachefs: bcachefs: copygc now skips non-rw devices bcachefs: Fix bch2_dev_journal_alloc() spuriously failing bcachefs: Don't set BCH_FEATURE_incompat_version_field unless requested
2025-03-06bcachefs: copygc now skips non-rw devicesKent Overstreet
There's no point in doing copygc on non-rw devices: the fragmentation doesn't matter if we're not writing to them, and we may not have anywhere to put the data on our other devices. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-03-06bcachefs: Fix bch2_dev_journal_alloc() spuriously failingKent Overstreet
Previously, we fixed journal resize spuriousl failing with -BCH_ERR_open_buckets_empty, but initial journal allocation was missed because it didn't invoke the "block on allocator" loop at all. Factor out the "loop on allocator" code to fix that. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-03-07Merge tag 'drm-xe-fixes-2025-03-06' of ↵Dave Airlie
https://gitlab.freedesktop.org/drm/xe/kernel into drm-fixes - Remove double page flip on initial plane (Maarten) - Properly setup userptr pfn_flags_mask (Auld) - Fix GT "for each engine" workarounds (Tvrtko) - Fix userptr races and missed validations (Thomas, Brost) - Userptr invalid page access fixes (Thomas) Signed-off-by: Dave Airlie <airlied@redhat.com> From: Rodrigo Vivi <rodrigo.vivi@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/Z8ni6w3tskCFL11O@intel.com
2025-03-07Merge tag 'drm-intel-fixes-2025-03-06' of ↵Dave Airlie
https://gitlab.freedesktop.org/drm/i915/kernel into drm-fixes - DP MST fix (Jani) Signed-off-by: Dave Airlie <airlied@redhat.com> From: Rodrigo Vivi <rodrigo.vivi@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/Z8ng8NjmRGiVcb5t@intel.com
2025-03-07Merge tag 'drm-misc-fixes-2025-03-06' of ↵Dave Airlie
https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes A Kconfig fix for nouveau, locking and timestamp fixes for imagination, a header guard fix for sched and a DPMS regression fix for bochs. Signed-off-by: Dave Airlie <airlied@redhat.com> From: Maxime Ripard <mripard@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250306-antelope-of-imminent-anger-bca19e@houat
2025-03-06Merge tag 'net-6.14-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Paolo Abeni: "Including fixes from bluetooth and wireless. Current release - new code bugs: - wifi: nl80211: disable multi-link reconfiguration Previous releases - regressions: - gso: fix ownership in __udp_gso_segment - wifi: iwlwifi: - fix A-MSDU TSO preparation - free pages allocated when failing to build A-MSDU - ipv6: fix dst ref loop in ila lwtunnel - mptcp: fix 'scheduling while atomic' in mptcp_pm_nl_append_new_local_addr - bluetooth: add check for mgmt_alloc_skb() in mgmt_device_connected() - ethtool: allow NULL nlattrs when getting a phy_device - eth: be2net: fix sleeping while atomic bugs in be_ndo_bridge_getlink Previous releases - always broken: - core: support TCP GSO case for a few missing flags - wifi: mac80211: - fix vendor-specific inheritance - cleanup sta TXQs on flush - llc: do not use skb_get() before dev_queue_xmit() - eth: ipa: nable checksum for IPA_ENDPOINT_AP_MODEM_{RX,TX} for v4.7" * tag 'net-6.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (41 commits) net: ipv6: fix missing dst ref drop in ila lwtunnel net: ipv6: fix dst ref loop in ila lwtunnel mctp i3c: handle NULL header address net: dsa: mt7530: Fix traffic flooding for MMIO devices net-timestamp: support TCP GSO case for a few missing flags vlan: enforce underlying device type mptcp: fix 'scheduling while atomic' in mptcp_pm_nl_append_new_local_addr net: ethtool: netlink: Allow NULL nlattrs when getting a phy_device ppp: Fix KMSAN uninit-value warning with bpf net: ipa: Enable checksum for IPA_ENDPOINT_AP_MODEM_{RX,TX} for v4.7 net: ipa: Fix QSB data for v4.7 net: ipa: Fix v4.7 resource group names net: hns3: make sure ptp clock is unregister and freed if hclge_ptp_get_cycle returns an error wifi: nl80211: disable multi-link reconfiguration net: dsa: rtl8366rb: don't prompt users for LED control be2net: fix sleeping while atomic bugs in be_ndo_bridge_getlink llc: do not use skb_get() before dev_queue_xmit() wifi: cfg80211: regulatory: improve invalid hints checking caif_virtio: fix wrong pointer check in cfv_probe() net: gso: fix ownership in __udp_gso_segment ...
2025-03-06Merge tag 'v6.14-rc5-smb3-fixes' of git://git.samba.org/ksmbdLinus Torvalds
Pull smb fixes from Steve French: "Five SMB server fixes, two related client fixes, and minor MAINTAINERS update: - Two SMB3 lock fixes fixes (including use after free and bug on fix) - Fix to race condition that can happen in processing IPC responses - Four ACL related fixes: one related to endianness of num_aces, and two related fixes to the checks for num_aces (for both client and server), and one fixing missing check for num_subauths which can cause memory corruption - And minor update to email addresses in MAINTAINERS file" * tag 'v6.14-rc5-smb3-fixes' of git://git.samba.org/ksmbd: cifs: fix incorrect validation for num_aces field of smb_acl ksmbd: fix incorrect validation for num_aces field of smb_acl smb: common: change the data type of num_aces to le16 ksmbd: fix bug on trap in smb2_lock ksmbd: fix use-after-free in smb2_lock ksmbd: fix type confusion via race condition when using ipc_msg_send_request ksmbd: fix out-of-bounds in parse_sec_desc() MAINTAINERS: update email address in cifs and ksmbd entry
2025-03-06Merge tag 'exfat-for-6.14-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat Pull exfat fixes from Namjae Jeon: - Optimize new cluster allocation by correctly find empty entry slot - Add a check to prevent excessive bitmap clearing due to invalid data size of file/dir entry - Fix incorrect error return for zero-byte writes * tag 'exfat-for-6.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat: exfat: add a check for invalid data size exfat: short-circuit zero-byte writes in exfat_file_write_iter exfat: fix soft lockup in exfat_clear_bitmap exfat: fix just enough dentries but allocate a new cluster to dir
2025-03-06Merge tag 'vfs-6.14-rc6.fixes' of ↵Linus Torvalds
gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull vfs fixes from Christian Brauner: - Fix spelling mistakes in idmappings.rst - Fix RCU warnings in override_creds()/revert_creds() - Create new pid namespaces with default limit now that pid_max is namespaced * tag 'vfs-6.14-rc6.fixes' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: pid: Do not set pid_max in new pid namespaces doc: correcting two prefix errors in idmappings.rst cred: Fix RCU warnings in override/revert_creds
2025-03-06fs/pipe: fix pipe buffer index use in FUSELinus Torvalds
This was another case that Rasmus pointed out where the direct access to the pipe head and tail pointers broke on 32-bit configurations due to the type changes. As with the pipe FIONREAD case, fix it by using the appropriate helper functions that deal with the right pipe index sizing. Reported-by: Rasmus Villemoes <ravi@prevas.dk> Link: https://lore.kernel.org/all/878qpi5wz4.fsf@prevas.dk/ Fixes: 3d252160b818 ("fs/pipe: Read pipe->{head,tail} atomically outside pipe->mutex")Cc: Oleg > Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: K Prateek Nayak <kprateek.nayak@amd.com> Cc: Swapnil Sapkal <swapnil.sapkal@amd.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-03-06fs/pipe: do not open-code pipe head/tail logic in FIONREADLinus Torvalds
Rasmus points out that we do indeed have other cases of breakage from the type changes that were introduced on 32-bit targets in order to read the pipe head and tail values atomically (commit 3d252160b818: "fs/pipe: Read pipe->{head,tail} atomically outside pipe->mutex"). Fix it up by using the proper helper functions that now deal with the pipe buffer index types properly. This makes the code simpler and more obvious. The compiler does the CSE and loop hoisting of the pipe ring size masking that we used to do manually, so open-coding this was never a good idea. Reported-by: Rasmus Villemoes <ravi@prevas.dk> Link: https://lore.kernel.org/all/87cyeu5zgk.fsf@prevas.dk/ Fixes: 3d252160b818 ("fs/pipe: Read pipe->{head,tail} atomically outside pipe->mutex")Cc: Oleg Nesterov <oleg@redhat.com> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: K Prateek Nayak <kprateek.nayak@amd.com> Cc: Swapnil Sapkal <swapnil.sapkal@amd.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-03-06fs/pipe: express 'pipe_empty()' in terms of 'pipe_occupancy()'Linus Torvalds
That's what 'pipe_full()' does, so it's more consistent. But more importantly it gets the type limits right when the pipe head and tail are no longer necessarily 'unsigned int'. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-03-06net: ipv6: fix missing dst ref drop in ila lwtunnelJustin Iurman
Add missing skb_dst_drop() to drop reference to the old dst before adding the new dst to the skb. Fixes: 79ff2fc31e0f ("ila: Cache a route to translated address") Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Justin Iurman <justin.iurman@uliege.be> Link: https://patch.msgid.link/20250305081655.19032-1-justin.iurman@uliege.be Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-06net: ipv6: fix dst ref loop in ila lwtunnelJustin Iurman
This patch follows commit 92191dd10730 ("net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels") and, on a second thought, the same patch is also needed for ila (even though the config that triggered the issue was pathological, but still, we don't want that to happen). Fixes: 79ff2fc31e0f ("ila: Cache a route to translated address") Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Justin Iurman <justin.iurman@uliege.be> Link: https://patch.msgid.link/20250304181039.35951-1-justin.iurman@uliege.be Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-06mctp i3c: handle NULL header addressMatt Johnston
daddr can be NULL if there is no neighbour table entry present, in that case the tx packet should be dropped. saddr will usually be set by MCTP core, but check for NULL in case a packet is transmitted by a different protocol. Signed-off-by: Matt Johnston <matt@codeconstruct.com.au> Fixes: c8755b29b58e ("mctp i3c: MCTP I3C driver") Link: https://patch.msgid.link/20250304-mctp-i3c-null-v1-1-4416bbd56540@codeconstruct.com.au Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-06pid: Do not set pid_max in new pid namespacesMichal Koutný
It is already difficult for users to troubleshoot which of multiple pid limits restricts their workload. The per-(hierarchical-)NS pid_max would contribute to the confusion. Also, the implementation copies the limit upon creation from parent, this pattern showed cumbersome with some attributes in legacy cgroup controllers -- it's subject to race condition between parent's limit modification and children creation and once copied it must be changed in the descendant. Let's do what other places do (ucounts or cgroup limits) -- create new pid namespaces without any limit at all. The global limit (actually any ancestor's limit) is still effectively in place, we avoid the set/unshare race and bumps of global (ancestral) limit have the desired effect on pid namespace that do not care. Link: https://lore.kernel.org/r/20240408145819.8787-1-mkoutny@suse.com/ Link: https://lore.kernel.org/r/20250221170249.890014-1-mkoutny@suse.com/ Fixes: 7863dcc72d0f4 ("pid: allow pid_max to be set per pid namespace") Signed-off-by: Michal Koutný <mkoutny@suse.com> Link: https://lore.kernel.org/r/20250305145849.55491-1-mkoutny@suse.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-06drm/bochs: Fix DPMS regressionTakashi Iwai
The recent rewrite with the use of regular atomic helpers broke the DPMS unblanking on X11. Fix it by moving the call of bochs_hw_blank(false) from CRTC mode_set_nofb() to atomic_enable(). Fixes: 2037174993c8 ("drm/bochs: Use regular atomic helpers") Link: https://bugzilla.suse.com/show_bug.cgi?id=1238209 Signed-off-by: Takashi Iwai <tiwai@suse.de> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20250304134203.20534-1-tiwai@suse.de
2025-03-05net: dsa: mt7530: Fix traffic flooding for MMIO devicesLorenzo Bianconi
On MMIO devices (e.g. MT7988 or EN7581) unicast traffic received on lanX port is flooded on all other user ports if the DSA switch is configured without VLAN support since PORT_MATRIX in PCR regs contains all user ports. Similar to MDIO devices (e.g. MT7530 and MT7531) fix the issue defining default VLAN-ID 0 for MT7530 MMIO devices. Fixes: 110c18bfed414 ("net: dsa: mt7530: introduce driver for MT7988 built-in switch") Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Reviewed-by: Chester A. Unal <chester.a.unal@arinc9.com> Link: https://patch.msgid.link/20250304-mt7988-flooding-fix-v1-1-905523ae83e9@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-05drm/xe/userptr: Unmap userptrs in the mmu notifierThomas Hellström
If userptr pages are freed after a call to the xe mmu notifier, the device will not be blocked out from theoretically accessing these pages unless they are also unmapped from the iommu, and this violates some aspects of the iommu-imposed security. Ensure that userptrs are unmapped in the mmu notifier to mitigate this. A naive attempt would try to free the sg table, but the sg table itself may be accessed by a concurrent bind operation, so settle for only unmapping. v3: - Update lockdep asserts. - Fix a typo (Matthew Auld) Fixes: 81e058a3e7fd ("drm/xe: Introduce helper to populate userptr") Cc: Oak Zeng <oak.zeng@intel.com> Cc: Matthew Auld <matthew.auld@intel.com> Cc: <stable@vger.kernel.org> # v6.10+ Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Auld <matthew.auld@intel.com> Acked-by: Matthew Brost <matthew.brost@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250304173342.22009-4-thomas.hellstrom@linux.intel.com (cherry picked from commit ba767b9d01a2c552d76cf6f46b125d50ec4147a6) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2025-03-05drm/xe/hmm: Don't dereference struct page pointers without notifier lockThomas Hellström
The pnfs that we obtain from hmm_range_fault() point to pages that we don't have a reference on, and the guarantee that they are still in the cpu page-tables is that the notifier lock must be held and the notifier seqno is still valid. So while building the sg table and marking the pages accesses / dirty we need to hold this lock with a validated seqno. However, the lock is reclaim tainted which makes sg_alloc_table_from_pages_segment() unusable, since it internally allocates memory. Instead build the sg-table manually. For the non-iommu case this might lead to fewer coalesces, but if that's a problem it can be fixed up later in the resource cursor code. For the iommu case, the whole sg-table may still be coalesced to a single contigous device va region. This avoids marking pages that we don't own dirty and accessed, and it also avoid dereferencing struct pages that we don't own. v2: - Use assert to check whether hmm pfns are valid (Matthew Auld) - Take into account that large pages may cross range boundaries (Matthew Auld) v3: - Don't unnecessarily check for a non-freed sg-table. (Matthew Auld) - Add a missing up_read() in an error path. (Matthew Auld) Fixes: 81e058a3e7fd ("drm/xe: Introduce helper to populate userptr") Cc: Oak Zeng <oak.zeng@intel.com> Cc: <stable@vger.kernel.org> # v6.10+ Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Auld <matthew.auld@intel.com> Acked-by: Matthew Brost <matthew.brost@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250304173342.22009-3-thomas.hellstrom@linux.intel.com (cherry picked from commit ea3e66d280ce2576664a862693d1da8fd324c317) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2025-03-05drm/xe/hmm: Style- and include fixesThomas Hellström
Add proper #ifndef around the xe_hmm.h header, proper spacing and since the documentation mostly follows kerneldoc format, make it kerneldoc. Also prepare for upcoming -stable fixes. Fixes: 81e058a3e7fd ("drm/xe: Introduce helper to populate userptr") Cc: Oak Zeng <oak.zeng@intel.com> Cc: <stable@vger.kernel.org> # v6.10+ Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Auld <matthew.auld@intel.com> Acked-by: Matthew Brost <Matthew Brost <matthew.brost@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250304173342.22009-2-thomas.hellstrom@linux.intel.com (cherry picked from commit bbe2b06b55bc061c8fcec034ed26e88287f39143) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2025-03-05drm/xe: Add staging tree for VM bindsMatthew Brost
Concurrent VM bind staging and zapping of PTEs from a userptr notifier do not work because the view of PTEs is not stable. VM binds cannot acquire the notifier lock during staging, as memory allocations are required. To resolve this race condition, use a staging tree for VM binds that is committed only under the userptr notifier lock during the final step of the bind. This ensures a consistent view of the PTEs in the userptr notifier. A follow up may only use staging for VM in fault mode as this is the only mode in which the above race exists. v3: - Drop zap PTE change (Thomas) - s/xe_pt_entry/xe_pt_entry_staging (Thomas) Suggested-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: <stable@vger.kernel.org> Fixes: e8babb280b5e ("drm/xe: Convert multiple bind ops into single job") Fixes: a708f6501c69 ("drm/xe: Update PT layer with better error handling") Signed-off-by: Matthew Brost <matthew.brost@intel.com> Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250228073058.59510-5-thomas.hellstrom@linux.intel.com Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> (cherry picked from commit 6f39b0c5ef0385eae586760d10b9767168037aa5) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2025-03-05drm/xe: Fix fault mode invalidation with unbindThomas Hellström
Fix fault mode invalidation racing with unbind leading to the PTE zapping potentially traversing an invalid page-table tree. Do this by holding the notifier lock across PTE zapping. This might transfer any contention waiting on the notifier seqlock read side to the notifier lock read side, but that shouldn't be a major problem. At the same time get rid of the open-coded invalidation in the bind code by relying on the notifier even when the vma bind is not yet committed. Finally let userptr invalidation call a dedicated xe_vm function performing a full invalidation. Fixes: e8babb280b5e ("drm/xe: Convert multiple bind ops into single job") Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Auld <matthew.auld@intel.com> Cc: <stable@vger.kernel.org> # v6.12+ Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250228073058.59510-4-thomas.hellstrom@linux.intel.com (cherry picked from commit 100a5b8dadfca50d91d9a4c9fc01431b42a25cab) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2025-03-05drm/xe/vm: Fix a misplaced #endifThomas Hellström
Fix a (harmless) misplaced #endif leading to declarations appearing multiple times. Fixes: 0eb2a18a8fad ("drm/xe: Implement VM snapshot support for BO's and userptr") Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: José Roberto de Souza <jose.souza@intel.com> Cc: <stable@vger.kernel.org> # v6.12+ Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Tejas Upadhyay <tejas.upadhyay@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250228073058.59510-3-thomas.hellstrom@linux.intel.com (cherry picked from commit fcc20a4c752214b3e25632021c57d7d1d71ee1dd) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2025-03-05drm/xe/vm: Validate userptr during gpu vma prefetchingThomas Hellström
If a userptr vma subject to prefetching was already invalidated or invalidated during the prefetch operation, the operation would repeatedly return -EAGAIN which would typically cause an infinite loop. Validate the userptr to ensure this doesn't happen. v2: - Don't fallthrough from UNMAP to PREFETCH (Matthew Brost) Fixes: 5bd24e78829a ("drm/xe/vm: Subclass userptr vmas") Fixes: 617eebb9c480 ("drm/xe: Fix array of binds") Cc: Matthew Brost <matthew.brost@intel.com> Cc: <stable@vger.kernel.org> # v6.9+ Suggested-by: Matthew Brost <matthew.brost@intel.com> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250228073058.59510-2-thomas.hellstrom@linux.intel.com (cherry picked from commit 03c346d4d0d85d210d549d43c8cfb3dfb7f20e0a) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2025-03-05Merge tag 'hid-for-linus-2025030501' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid Pull HID fixes from Jiri Kosina: - power management fix in intel-thc-hid (Even Xu) - nintendo gencon mapping fix (Ryan McClelland) - fix for UAF on device diconnect path in hid-steam (Vicki Pfau) - two fixes for UAF on device disconnect path in intel-ish-hid (Zhang Lixu) - fix for potential NULL dereference in hid-appleir (Daniil Dulov) - few other small cosmetic fixes (e.g. typos) * tag 'hid-for-linus-2025030501' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid: HID: Intel-thc-hid: Intel-quickspi: Correct device state after S4 HID: intel-thc-hid: Fix spelling mistake "intput" -> "input" HID: hid-steam: Fix use-after-free when detaching device HID: debug: Fix spelling mistake "Messanger" -> "Messenger" HID: appleir: Fix potential NULL dereference at raw event handle HID: apple: disable Fn key handling on the Omoton KB066 HID: i2c-hid: improve i2c_hid_get_report error message HID: intel-ish-hid: Fix use-after-free issue in ishtp_hid_remove() HID: intel-ish-hid: Fix use-after-free issue in hid_ishtp_cl_remove() HID: google: fix unused variable warning under !CONFIG_ACPI HID: nintendo: fix gencon button events map HID: corsair-void: Update power supply values with a unified work handler
2025-03-05fs/pipe: remove buggy and unused 'helper' functionLinus Torvalds
While looking for incorrect users of the pipe head/tail fields (see commit c27c66afc449: "fs/pipe: Fix pipe_occupancy() with 16-bit indexes"), I found a bug in pipe_discard_from() that looked entirely broken. However, the fix is trivial: this buggy function isn't actually called by anything, so let's just remove it ASAP. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-03-05drm/amd/pm: always allow ih interrupt from fwKenneth Feng
always allow ih interrupt from fw on smu v14 based on the interface requirement Signed-off-by: Kenneth Feng <kenneth.feng@amd.com> Reviewed-by: Yang Wang <kevinyang.wang@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit a3199eba46c54324193607d9114a1e321292d7a1) Cc: stable@vger.kernel.org # 6.12.x
2025-03-05drm/radeon: Fix rs400_gpu_init for ATI mobility radeon Xpress 200MRichard Thier
num_gb_pipes was set to a wrong value using r420_pipe_config This have lead to HyperZ glitches on fast Z clearing. Closes: https://bugs.freedesktop.org/show_bug.cgi?id=110897 Reviewed-by: Marek Olšák <marek.olsak@amd.com> Signed-off-by: Richard Thier <u9vata@gmail.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit 044e59a85c4d84e3c8d004c486e5c479640563a6) Cc: stable@vger.kernel.org
2025-03-05include/linux/pipe_fs_i: Add htmldoc annotation for "head_tail" memberK Prateek Nayak
Add htmldoc annotation for the newly introduced "head_tail" member describing it to be a union of the pipe_inode_info's @head and @tail members. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/lkml/20250305204609.5e64768e@canb.auug.org.au/ Fixes: 3d252160b818 ("fs/pipe: Read pipe->{head,tail} atomically outside pipe->mutex") Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-03-05fs/pipe: Fix pipe_occupancy() with 16-bit indexesLinus Torvalds
The pipe_occupancy() logic implicitly relied on the natural unsigned modulo arithmetic in C, but that doesn't work for the new 'pipe_index_t' case, since any arithmetic will be done in 'int' (and here we had also made it 'unsigned int' due to the function call boundary). So make the modulo arithmetic explicit by casting the result to the proper type. Cc: Oleg Nesterov <oleg@redhat.com> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Swapnil Sapkal <swapnil.sapkal@amd.com> Cc: Alexey Gladkov <legion@kernel.org> Cc: K Prateek Nayak <kprateek.nayak@amd.com> Link: https://lore.kernel.org/all/CAHk-=wjyHsGLx=rxg6PKYBNkPYAejgo7=CbyL3=HGLZLsAaJFQ@mail.gmail.com/ Fixes: 3d252160b818 ("fs/pipe: Read pipe->{head,tail} atomically outside pipe->mutex") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-03-05drm/amdkfd: Fix NULL Pointer Dereference in KFD queueAndrew Martin
Through KFD IOCTL Fuzzing we encountered a NULL pointer derefrence when calling kfd_queue_acquire_buffers. Fixes: 629568d25fea ("drm/amdkfd: Validate queue cwsr area and eop buffer size") Signed-off-by: Andrew Martin <Andrew.Martin@amd.com> Reviewed-by: Philip Yang <Philip.Yang@amd.com> Signed-off-by: Andrew Martin <Andrew.Martin@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit 049e5bf3c8406f87c3d8e1958e0a16804fa1d530) Cc: stable@vger.kernel.org
2025-03-05drm/amd/display: Fix null check for pipe_ctx->plane_state in ↵Ma Ke
resource_build_scaling_params Null pointer dereference issue could occur when pipe_ctx->plane_state is null. The fix adds a check to ensure 'pipe_ctx->plane_state' is not null before accessing. This prevents a null pointer dereference. Found by code review. Fixes: 3be5262e353b ("drm/amd/display: Rename more dc_surface stuff to plane_state") Reviewed-by: Alex Hung <alex.hung@amd.com> Signed-off-by: Ma Ke <make24@iscas.ac.cn> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit 63e6a77ccf239337baa9b1e7787cde9fa0462092) Cc: stable@vger.kernel.org
2025-03-05net-timestamp: support TCP GSO case for a few missing flagsJason Xing
When I read through the TSO codes, I found out that we probably miss initializing the tx_flags of last seg when TSO is turned off, which means at the following points no more timestamp (for this last one) will be generated. There are three flags to be handled in this patch: 1. SKBTX_HW_TSTAMP 2. SKBTX_BPF 3. SKBTX_SCHED_TSTAMP Note that SKBTX_BPF[1] was added in 6.14.0-rc2 by commit 6b98ec7e882af ("bpf: Add BPF_SOCK_OPS_TSTAMP_SCHED_CB callback") and only belongs to net-next branch material for now. The common issue of the above three flags can be fixed by this single patch. This patch initializes the tx_flags to SKBTX_ANY_TSTAMP like what the UDP GSO does to make the newly segmented last skb inherit the tx_flags so that requested timestamp will be generated in each certain layer, or else that last one has zero value of tx_flags which leads to no timestamp at all. Fixes: 4ed2d765dfacc ("net-timestamp: TCP timestamping") Signed-off-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2025-03-05exfat: add a check for invalid data sizeYuezhang Mo
Add a check for invalid data size to avoid corrupted filesystem from being further corrupted. Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2025-03-05exfat: short-circuit zero-byte writes in exfat_file_write_iterEric Sandeen
When generic_write_checks() returns zero, it means that iov_iter_count() is zero, and there is no work to do. Simply return success like all other filesystems do, rather than proceeding down the write path, which today yields an -EFAULT in generic_perform_write() via the (fault_in_iov_iter_readable(i, bytes) == bytes) check when bytes == 0. Fixes: 11a347fb6cef ("exfat: change to get file size from DataLength") Reported-by: Noah <kernel-org-10@maxgrass.eu> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2025-03-05exfat: fix soft lockup in exfat_clear_bitmapNamjae Jeon
bitmap clear loop will take long time in __exfat_free_cluster() if data size of file/dir enty is invalid. If cluster bit in bitmap is already clear, stop clearing bitmap go to out of loop. Fixes: 31023864e67a ("exfat: add fat entry operations") Reported-by: Kun Hu <huk23@m.fudan.edu.cn>, Jiaji Qin <jjtan24@m.fudan.edu.cn> Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2025-03-05exfat: fix just enough dentries but allocate a new cluster to dirYuezhang Mo
This commit fixes the condition for allocating cluster to parent directory to avoid allocating new cluster to parent directory when there are just enough empty directory entries at the end of the parent directory. Fixes: af02c72d0b62 ("exfat: convert exfat_find_empty_entry() to use dentry cache") Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2025-03-05doc: correcting two prefix errors in idmappings.rstAiden Ma
Add the 'k' prefix to id 21000. And id `u1000` in the third idmapping should be mapped to `k31000`, not `u31000`. Signed-off-by: Aiden Ma <jiaheng.ma@foxmail.com> Link: https://lore.kernel.org/r/tencent_4E7B1F143E8051530C21FCADF4E014DCBB06@qq.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-04Merge tag 'x86_microcode_for_v6.14_rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull AMD microcode loading fixes from Borislav Petkov: - Load only sha256-signed microcode patch blobs - Other good cleanups * tag 'x86_microcode_for_v6.14_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/microcode/AMD: Load only SHA256-checksummed patches x86/microcode/AMD: Add get_patch_level() x86/microcode/AMD: Get rid of the _load_microcode_amd() forward declaration x86/microcode/AMD: Merge early_apply_microcode() into its single callsite x86/microcode/AMD: Remove unused save_microcode_in_initrd_amd() declarations x86/microcode/AMD: Remove ugly linebreak in __verify_patch_section() signature
2025-03-04vlan: enforce underlying device typeOscar Maes
Currently, VLAN devices can be created on top of non-ethernet devices. Besides the fact that it doesn't make much sense, this also causes a bug which leaks the address of a kernel function to usermode. When creating a VLAN device, we initialize GARP (garp_init_applicant) and MRP (mrp_init_applicant) for the underlying device. As part of the initialization process, we add the multicast address of each applicant to the underlying device, by calling dev_mc_add. __dev_mc_add uses dev->addr_len to determine the length of the new multicast address. This causes an out-of-bounds read if dev->addr_len is greater than 6, since the multicast addresses provided by GARP and MRP are only 6 bytes long. This behaviour can be reproduced using the following commands: ip tunnel add gretest mode ip6gre local ::1 remote ::2 dev lo ip l set up dev gretest ip link add link gretest name vlantest type vlan id 100 Then, the following command will display the address of garp_pdu_rcv: ip maddr show | grep 01:80:c2:00:00:21 Fix the bug by enforcing the type of the underlying device during VLAN device initialization. Fixes: 22bedad3ce11 ("net: convert multicast list to list_head") Reported-by: syzbot+91161fe81857b396c8a0@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/000000000000ca9a81061a01ec20@google.com/ Signed-off-by: Oscar Maes <oscmaes92@gmail.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://patch.msgid.link/20250303155619.8918-1-oscmaes92@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-04mptcp: fix 'scheduling while atomic' in mptcp_pm_nl_append_new_local_addrKrister Johansen
If multiple connection requests attempt to create an implicit mptcp endpoint in parallel, more than one caller may end up in mptcp_pm_nl_append_new_local_addr because none found the address in local_addr_list during their call to mptcp_pm_nl_get_local_id. In this case, the concurrent new_local_addr calls may delete the address entry created by the previous caller. These deletes use synchronize_rcu, but this is not permitted in some of the contexts where this function may be called. During packet recv, the caller may be in a rcu read critical section and have preemption disabled. An example stack: BUG: scheduling while atomic: swapper/2/0/0x00000302 Call Trace: <IRQ> dump_stack_lvl (lib/dump_stack.c:117 (discriminator 1)) dump_stack (lib/dump_stack.c:124) __schedule_bug (kernel/sched/core.c:5943) schedule_debug.constprop.0 (arch/x86/include/asm/preempt.h:33 kernel/sched/core.c:5970) __schedule (arch/x86/include/asm/jump_label.h:27 include/linux/jump_label.h:207 kernel/sched/features.h:29 kernel/sched/core.c:6621) schedule (arch/x86/include/asm/preempt.h:84 kernel/sched/core.c:6804 kernel/sched/core.c:6818) schedule_timeout (kernel/time/timer.c:2160) wait_for_completion (kernel/sched/completion.c:96 kernel/sched/completion.c:116 kernel/sched/completion.c:127 kernel/sched/completion.c:148) __wait_rcu_gp (include/linux/rcupdate.h:311 kernel/rcu/update.c:444) synchronize_rcu (kernel/rcu/tree.c:3609) mptcp_pm_nl_append_new_local_addr (net/mptcp/pm_netlink.c:966 net/mptcp/pm_netlink.c:1061) mptcp_pm_nl_get_local_id (net/mptcp/pm_netlink.c:1164) mptcp_pm_get_local_id (net/mptcp/pm.c:420) subflow_check_req (net/mptcp/subflow.c:98 net/mptcp/subflow.c:213) subflow_v4_route_req (net/mptcp/subflow.c:305) tcp_conn_request (net/ipv4/tcp_input.c:7216) subflow_v4_conn_request (net/mptcp/subflow.c:651) tcp_rcv_state_process (net/ipv4/tcp_input.c:6709) tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1934) tcp_v4_rcv (net/ipv4/tcp_ipv4.c:2334) ip_protocol_deliver_rcu (net/ipv4/ip_input.c:205 (discriminator 1)) ip_local_deliver_finish (include/linux/rcupdate.h:813 net/ipv4/ip_input.c:234) ip_local_deliver (include/linux/netfilter.h:314 include/linux/netfilter.h:308 net/ipv4/ip_input.c:254) ip_sublist_rcv_finish (include/net/dst.h:461 net/ipv4/ip_input.c:580) ip_sublist_rcv (net/ipv4/ip_input.c:640) ip_list_rcv (net/ipv4/ip_input.c:675) __netif_receive_skb_list_core (net/core/dev.c:5583 net/core/dev.c:5631) netif_receive_skb_list_internal (net/core/dev.c:5685 net/core/dev.c:5774) napi_complete_done (include/linux/list.h:37 include/net/gro.h:449 include/net/gro.h:444 net/core/dev.c:6114) igb_poll (drivers/net/ethernet/intel/igb/igb_main.c:8244) igb __napi_poll (net/core/dev.c:6582) net_rx_action (net/core/dev.c:6653 net/core/dev.c:6787) handle_softirqs (kernel/softirq.c:553) __irq_exit_rcu (kernel/softirq.c:588 kernel/softirq.c:427 kernel/softirq.c:636) irq_exit_rcu (kernel/softirq.c:651) common_interrupt (arch/x86/kernel/irq.c:247 (discriminator 14)) </IRQ> This problem seems particularly prevalent if the user advertises an endpoint that has a different external vs internal address. In the case where the external address is advertised and multiple connections already exist, multiple subflow SYNs arrive in parallel which tends to trigger the race during creation of the first local_addr_list entries which have the internal address instead. Fix by skipping the replacement of an existing implicit local address if called via mptcp_pm_nl_get_local_id. Fixes: d045b9eb95a9 ("mptcp: introduce implicit endpoints") Cc: stable@vger.kernel.org Suggested-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Krister Johansen <kjlx@templeofstupid.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20250303-net-mptcp-fix-sched-while-atomic-v1-1-f6a216c5a74c@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-04net: ethtool: netlink: Allow NULL nlattrs when getting a phy_deviceMaxime Chevallier
ethnl_req_get_phydev() is used to lookup a phy_device, in the case an ethtool netlink command targets a specific phydev within a netdev's topology. It takes as a parameter a const struct nlattr *header that's used for error handling : if (!phydev) { NL_SET_ERR_MSG_ATTR(extack, header, "no phy matching phyindex"); return ERR_PTR(-ENODEV); } In the notify path after a ->set operation however, there's no request attributes available. The typical callsite for the above function looks like: phydev = ethnl_req_get_phydev(req_base, tb[ETHTOOL_A_XXX_HEADER], info->extack); So, when tb is NULL (such as in the ethnl notify path), we have a nice crash. It turns out that there's only the PLCA command that is in that case, as the other phydev-specific commands don't have a notification. This commit fixes the crash by passing the cmd index and the nlattr array separately, allowing NULL-checking it directly inside the helper. Fixes: c15e065b46dc ("net: ethtool: Allow passing a phy index for some commands") Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Reviewed-by: Kory Maincent <kory.maincent@bootlin.com> Reported-by: Parthiban Veerasooran <parthiban.veerasooran@microchip.com> Link: https://patch.msgid.link/20250301141114.97204-1-maxime.chevallier@bootlin.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-04ppp: Fix KMSAN uninit-value warning with bpfJiayuan Chen
Syzbot caught an "KMSAN: uninit-value" warning [1], which is caused by the ppp driver not initializing a 2-byte header when using socket filter. The following code can generate a PPP filter BPF program: ''' struct bpf_program fp; pcap_t *handle; handle = pcap_open_dead(DLT_PPP_PPPD, 65535); pcap_compile(handle, &fp, "ip and outbound", 0, 0); bpf_dump(&fp, 1); ''' Its output is: ''' (000) ldh [2] (001) jeq #0x21 jt 2 jf 5 (002) ldb [0] (003) jeq #0x1 jt 4 jf 5 (004) ret #65535 (005) ret #0 ''' Wen can find similar code at the following link: https://github.com/ppp-project/ppp/blob/master/pppd/options.c#L1680 The maintainer of this code repository is also the original maintainer of the ppp driver. As you can see the BPF program skips 2 bytes of data and then reads the 'Protocol' field to determine if it's an IP packet. Then it read the first byte of the first 2 bytes to determine the direction. The issue is that only the first byte indicating direction is initialized in current ppp driver code while the second byte is not initialized. For normal BPF programs generated by libpcap, uninitialized data won't be used, so it's not a problem. However, for carefully crafted BPF programs, such as those generated by syzkaller [2], which start reading from offset 0, the uninitialized data will be used and caught by KMSAN. [1] https://syzkaller.appspot.com/bug?extid=853242d9c9917165d791 [2] https://syzkaller.appspot.com/text?tag=ReproC&x=11994913980000 Cc: Paul Mackerras <paulus@samba.org> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+853242d9c9917165d791@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/000000000000dea025060d6bc3bc@google.com/ Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250228141408.393864-1-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>