kernel, branch linux-6.12.y

Linux 6.12.77

2026-03-13T16:20:49Z

Link: https://lore.kernel.org/r/20260312201018.128816016@linuxfoundation.org Tested-by: Brett A C Sheffield Tested-by: Shuah Khan Tested-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

ata: libata-eh: Fix detection of deferred qc timeouts

2026-03-13T16:20:49Z

commit ee0e6e69a772d601e152e5368a1da25d656122a8 upstream. If the ata_qc_for_each_raw() loop finishes without finding a matching SCSI command for any QC, the variable qc will hold a pointer to the last element examined, which has the tag i == ATA_MAX_QUEUE - 1. This qc can match the port deferred QC (ap->deferred_qc). If that happens, the condition qc == ap->deferred_qc evaluates to true despite the loop not breaking with a match on the SCSI command for this QC. In that case, the error handler mistakenly intercepts a command that has not been issued yet and that has not timed out, and thus erroneously returning a timeout error. Fix the problem by checking for i < ATA_MAX_QUEUE in addition to qc == ap->deferred_qc. The problem was found by an experimental code review agent based on gemini-3.1-pro while reviewing backports into v6.18.y. Assisted-by: Gemini:gemini-3.1-pro Fixes: eddb98ad9364 ("ata: libata-eh: correctly handle deferred qc timeouts") Signed-off-by: Guenter Roeck [cassel: modified commit log as suggested by Damien] Reviewed-by: Damien Le Moal Signed-off-by: Niklas Cassel Signed-off-by: Greg Kroah-Hartman

ata: libata: cancel pending work after clearing deferred_qc

2026-03-13T16:20:49Z

commit aac9b27f7c1f2b2cf7f50a9ca633ecbbcaf22af9 upstream. Syzbot reported a WARN_ON() in ata_scsi_deferred_qc_work(), caused by ap->ops->qc_defer() returning non-zero before issuing the deferred qc. ata_scsi_schedule_deferred_qc() is called during each command completion. This function will check if there is a deferred QC, and if ap->ops->qc_defer() returns zero, meaning that it is possible to queue the deferred qc at this time (without being deferred), then it will queue the work which will issue the deferred qc. Once the work get to run, which can potentially be a very long time after the work was scheduled, there is a WARN_ON() if ap->ops->qc_defer() returns non-zero. While we hold the ap->lock both when assigning and clearing deferred_qc, and the work itself holds the ap->lock, the code currently does not cancel the work after clearing the deferred qc. This means that the following scenario can happen: 1) One or several NCQ commands are queued. 2) A non-NCQ command is queued, gets stored in ap->deferred_qc. 3) Last NCQ command gets completed, work is queued to issue the deferred qc. 4) Timeout or error happens, ap->deferred_qc is cleared. The queued work is currently NOT canceled. 5) Port is reset. 6) One or several NCQ commands are queued. 7) A non-NCQ command is queued, gets stored in ap->deferred_qc. 8) Work is finally run. Yet at this time, there is still NCQ commands in flight. The work in 8) really belongs to the non-NCQ command in 2), not to the non-NCQ command in 7). The reason why the work is executed when it is not supposed to, is because it was never canceled when ap->deferred_qc was cleared in 4). Thus, ensure that we always cancel the work after clearing ap->deferred_qc. Another potential fix would have been to let ata_scsi_deferred_qc_work() do nothing if ap->ops->qc_defer() returns non-zero. However, canceling the work when clearing ap->deferred_qc seems slightly more logical, as we hold the ap->lock when clearing ap->deferred_qc, so we know that the work cannot be holding the lock. (The function could be waiting for the lock, but that is okay since it will do nothing if ap->deferred_qc is not set.) Reported-by: syzbot+bcaf842a1e8ead8dfb89@syzkaller.appspotmail.com Fixes: 0ea84089dbf6 ("ata: libata-scsi: avoid Non-NCQ command starvation") Fixes: eddb98ad9364 ("ata: libata-eh: correctly handle deferred qc timeouts") Reviewed-by: Igor Pylypiv Reviewed-by: Damien Le Moal Signed-off-by: Niklas Cassel Signed-off-by: Greg Kroah-Hartman

ata: libata-eh: correctly handle deferred qc timeouts

2026-03-13T16:20:49Z

commit eddb98ad9364b4e778768785d46cfab04ce52100 upstream. A deferred qc may timeout while waiting for the device queue to drain to be submitted. In such case, since the qc is not active, ata_scsi_cmd_error_handler() ends up calling scsi_eh_finish_cmd(), which frees the qc. But as the port deferred_qc field still references this finished/freed qc, the deferred qc work may eventually attempt to call ata_qc_issue() against this invalid qc, leading to errors such as reported by UBSAN (syzbot run): UBSAN: shift-out-of-bounds in drivers/ata/libata-core.c:5166:24 shift exponent 4210818301 is too large for 64-bit type 'long long unsigned int' ... Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 ubsan_epilogue+0xa/0x30 lib/ubsan.c:233 __ubsan_handle_shift_out_of_bounds+0x279/0x2a0 lib/ubsan.c:494 ata_qc_issue.cold+0x38/0x9f drivers/ata/libata-core.c:5166 ata_scsi_deferred_qc_work+0x154/0x1f0 drivers/ata/libata-scsi.c:1679 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Fix this by checking if the qc of a timed out SCSI command is a deferred one, and in such case, clear the port deferred_qc field and finish the SCSI command with DID_TIME_OUT. Reported-by: syzbot+1f77b8ca15336fff21ff@syzkaller.appspotmail.com Fixes: 0ea84089dbf6 ("ata: libata-scsi: avoid Non-NCQ command starvation") Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Igor Pylypiv Signed-off-by: Greg Kroah-Hartman

ata: libata-core: fix cancellation of a port deferred qc work

2026-03-13T16:20:49Z

commit 55db009926634b20955bd8abbee921adbc8d2cb4 upstream. cancel_work_sync() is a sleeping function so it cannot be called with the spin lock of a port being held. Move the call to this function in ata_port_detach() after EH completes, with the port lock released, together with other work cancellation calls. Fixes: 0ea84089dbf6 ("ata: libata-scsi: avoid Non-NCQ command starvation") Signed-off-by: Damien Le Moal Reviewed-by: Hannes Reinecke Reviewed-by: Igor Pylypiv Signed-off-by: Greg Kroah-Hartman

ext4: fix potential null deref in ext4_mb_init()

2026-03-13T16:20:48Z

commit 3c3fac6bc0a9c00dbe65d8dc0d3a282afe4d3188 upstream. In ext4_mb_init(), ext4_mb_avg_fragment_size_destroy() may be called when sbi->s_mb_avg_fragment_size remains uninitialized (e.g., if groupinfo slab cache allocation fails). Since ext4_mb_avg_fragment_size_destroy() lacks null pointer checking, this leads to a null pointer dereference. ================================================================== EXT4-fs: no memory for groupinfo slab cache BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: Oops: 0002 [#1] SMP PTI CPU:2 UID: 0 PID: 87 Comm:mount Not tainted 6.17.0-rc2 #1134 PREEMPT(none) RIP: 0010:_raw_spin_lock_irqsave+0x1b/0x40 Call Trace: xa_destroy+0x61/0x130 ext4_mb_init+0x483/0x540 __ext4_fill_super+0x116d/0x17b0 ext4_fill_super+0xd3/0x280 get_tree_bdev_flags+0x132/0x1d0 vfs_get_tree+0x29/0xd0 do_new_mount+0x197/0x300 __x64_sys_mount+0x116/0x150 do_syscall_64+0x50/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e ================================================================== Therefore, add necessary null check to ext4_mb_avg_fragment_size_destroy() to prevent this issue. The same fix is also applied to ext4_mb_largest_free_orders_destroy(). Reported-by: syzbot+1713b1aa266195b916c2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=1713b1aa266195b916c2 Cc: stable@kernel.org Fixes: f7eaacbb4e54 ("ext4: convert free groups order lists to xarrays") Signed-off-by: Baokun Li Reviewed-by: Zhang Yi Reviewed-by: Ritesh Harjani (IBM) Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

apparmor: fix race between freeing data and fs accessing it

2026-03-13T16:20:48Z

commit 8e135b8aee5a06c52a4347a5a6d51223c6f36ba3 upstream. AppArmor was putting the reference to i_private data on its end after removing the original entry from the file system. However the inode can aand does live beyond that point and it is possible that some of the fs call back functions will be invoked after the reference has been put, which results in a race between freeing the data and accessing it through the fs. While the rawdata/loaddata is the most likely candidate to fail the race, as it has the fewest references. If properly crafted it might be possible to trigger a race for the other types stored in i_private. Fix this by moving the put of i_private referenced data to the correct place which is during inode eviction. Fixes: c961ee5f21b20 ("apparmor: convert from securityfs to apparmorfs for policy ns files") Reported-by: Qualys Security Advisory Reviewed-by: Georgia Garcia Reviewed-by: Maxime Bélair Reviewed-by: Cengiz Can Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: fix race on rawdata dereference

2026-03-13T16:20:48Z

commit a0b7091c4de45a7325c8780e6934a894f92ac86b upstream. There is a race condition that leads to a use-after-free situation: because the rawdata inodes are not refcounted, an attacker can start open()ing one of the rawdata files, and at the same time remove the last reference to this rawdata (by removing the corresponding profile, for example), which frees its struct aa_loaddata; as a result, when seq_rawdata_open() is reached, i_private is a dangling pointer and freed memory is accessed. The rawdata inodes weren't refcounted to avoid a circular refcount and were supposed to be held by the profile rawdata reference. However during profile removal there is a window where the vfs and profile destruction race, resulting in the use after free. Fix this by moving to a double refcount scheme. Where the profile refcount on rawdata is used to break the circular dependency. Allowing for freeing of the rawdata once all inode references to the rawdata are put. Fixes: 5d5182cae401 ("apparmor: move to per loaddata files, instead of replicating in profiles") Reported-by: Qualys Security Advisory Reviewed-by: Georgia Garcia Reviewed-by: Maxime Bélair Reviewed-by: Cengiz Can Tested-by: Salvatore Bonaccorso Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: fix differential encoding verification

2026-03-13T16:20:48Z

commit 39440b137546a3aa383cfdabc605fb73811b6093 upstream. Differential encoding allows loops to be created if it is abused. To prevent this the unpack should verify that a diff-encode chain terminates. Unfortunately the differential encode verification had two bugs. 1. it conflated states that had gone through check and already been marked, with states that were currently being checked and marked. This means that loops in the current chain being verified are treated as a chain that has already been verified. 2. the order bailout on already checked states compared current chain check iterators j,k instead of using the outer loop iterator i. Meaning a step backwards in states in the current chain verification was being mistaken for moving to an already verified state. Move to a double mark scheme where already verified states get a different mark, than the current chain being kept. This enables us to also drop the backwards verification check that was the cause of the second error as any already verified state is already marked. Fixes: 031dcc8f4e84 ("apparmor: dfa add support for state differential encoding") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman

apparmor: fix unprivileged local user can do privileged policy management

2026-03-13T16:20:48Z

commit 6601e13e82841879406bf9f369032656f441a425 upstream. An unprivileged local user can load, replace, and remove profiles by opening the apparmorfs interfaces, via a confused deputy attack, by passing the opened fd to a privileged process, and getting the privileged process to write to the interface. This does require a privileged target that can be manipulated to do the write for the unprivileged process, but once such access is achieved full policy management is possible and all the possible implications that implies: removing confinement, DoS of system or target applications by denying all execution, by-passing the unprivileged user namespace restriction, to exploiting kernel bugs for a local privilege escalation. The policy management interface can not have its permissions simply changed from 0666 to 0600 because non-root processes need to be able to load policy to different policy namespaces. Instead ensure the task writing the interface has privileges that are a subset of the task that opened the interface. This is already done via policy for confined processes, but unconfined can delegate access to the opened fd, by-passing the usual policy check. Fixes: b7fd2c0340eac ("apparmor: add per policy ns .load, .replace, .remove interface files") Reported-by: Qualys Security Advisory Tested-by: Salvatore Bonaccorso Reviewed-by: Georgia Garcia Reviewed-by: Cengiz Can Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman