In the Linux kernel, the following vulnerability has been resolved:
ext4: avoid use-after-free in ext4_ext_show_leaf()
In ext4_find_extent(), path may be freed by error or be reallocated, so
using a previously saved *ppath may have been freed and thus may trigger
use-after-free, as follows:
ext4_split_extent
path = *ppath;
ext4_split_extent_at(ppath)
path = ext4_find_extent(ppath)
ext4_split_extent_at(ppath)
// ext4_find_extent fails to free path
// but zeroout succeeds
ext4_ext_show_leaf(inode, path)
eh = path[depth].p_hdr
// path use-after-free !!!
Similar to ext4_split_extent_at(), we use *ppath directly as an input to
ext4_ext_show_leaf(). Fix a spelling error by the way.
Same problem in ext4_ext_handle_unwritten_extents(). Since 'path' is only
used in ext4_ext_show_leaf(), remove 'path' and use *ppath directly.
This issue is triggered only when EXT_DEBUG is defined and therefore does
not affect functionality.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/pm: ensure the fw_info is not null before using it
This resolves the dereference null return value warning
reported by Coverity.
In the Linux kernel, the following vulnerability has been resolved:
scsi: lpfc: Validate hdwq pointers before dereferencing in reset/errata paths
When the HBA is undergoing a reset or is handling an errata event, NULL ptr
dereference crashes may occur in routines such as
lpfc_sli_flush_io_rings(), lpfc_dev_loss_tmo_callbk(), or
lpfc_abort_handler().
Add NULL ptr checks before dereferencing hdwq pointers that may have been
freed due to operations colliding with a reset or errata event handler.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Initialize get_bytes_per_element's default to 1
Variables, used as denominators and maybe not assigned to other values,
should not be 0. bytes_per_element_y & bytes_per_element_c are
initialized by get_bytes_per_element() which should never return 0.
This fixes 10 DIVIDE_BY_ZERO issues reported by Coverity.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check stream_status before it is used
[WHAT & HOW]
dc_state_get_stream_status can return null, and therefore null must be
checked before stream_status is used.
This fixes 1 NULL_RETURNS issue reported by Coverity.
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix index out of bounds in degamma hardware format translation
Fixes index out of bounds issue in
`cm_helper_translate_curve_to_degamma_hw_format` function. The issue
could occur when the index 'i' exceeds the number of transfer function
points (TRANSFER_FUNC_POINTS).
The fix adds a check to ensure 'i' is within bounds before accessing the
transfer function points. If 'i' is out of bounds the function returns
false to indicate an error.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:594 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.red' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:595 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.green' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_cm_common.c:596 cm_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.blue' 1025 <= s32max
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix index out of bounds in DCN30 degamma hardware format translation
This commit addresses a potential index out of bounds issue in the
`cm3_helper_translate_curve_to_degamma_hw_format` function in the DCN30
color management module. The issue could occur when the index 'i'
exceeds the number of transfer function points (TRANSFER_FUNC_POINTS).
The fix adds a check to ensure 'i' is within bounds before accessing the
transfer function points. If 'i' is out of bounds, the function returns
false to indicate an error.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn30/dcn30_cm_common.c:338 cm3_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.red' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn30/dcn30_cm_common.c:339 cm3_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.green' 1025 <= s32max
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn30/dcn30_cm_common.c:340 cm3_helper_translate_curve_to_degamma_hw_format() error: buffer overflow 'output_tf->tf_pts.blue' 1025 <= s32max
In the Linux kernel, the following vulnerability has been resolved:
btrfs: wait for fixup workers before stopping cleaner kthread during umount
During unmount, at close_ctree(), we have the following steps in this order:
1) Park the cleaner kthread - this doesn't destroy the kthread, it basically
halts its execution (wake ups against it work but do nothing);
2) We stop the cleaner kthread - this results in freeing the respective
struct task_struct;
3) We call btrfs_stop_all_workers() which waits for any jobs running in all
the work queues and then free the work queues.
Syzbot reported a case where a fixup worker resulted in a crash when doing
a delayed iput on its inode while attempting to wake up the cleaner at
btrfs_add_delayed_iput(), because the task_struct of the cleaner kthread
was already freed. This can happen during unmount because we don't wait
for any fixup workers still running before we call kthread_stop() against
the cleaner kthread, which stops and free all its resources.
Fix this by waiting for any fixup workers at close_ctree() before we call
kthread_stop() against the cleaner and run pending delayed iputs.
The stack traces reported by syzbot were the following:
BUG: KASAN: slab-use-after-free in __lock_acquire+0x77/0x2050 kernel/locking/lockdep.c:5065
Read of size 8 at addr ffff8880272a8a18 by task kworker/u8:3/52
CPU: 1 UID: 0 PID: 52 Comm: kworker/u8:3 Not tainted 6.12.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: btrfs-fixup btrfs_work_helper
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
__lock_acquire+0x77/0x2050 kernel/locking/lockdep.c:5065
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:551 [inline]
try_to_wake_up+0xb0/0x1480 kernel/sched/core.c:4154
btrfs_writepage_fixup_worker+0xc16/0xdf0 fs/btrfs/inode.c:2842
btrfs_work_helper+0x390/0xc50 fs/btrfs/async-thread.c:314
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
worker_thread+0x870/0xd30 kernel/workqueue.c:3391
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Allocated by task 2:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:247 [inline]
slab_post_alloc_hook mm/slub.c:4086 [inline]
slab_alloc_node mm/slub.c:4135 [inline]
kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4187
alloc_task_struct_node kernel/fork.c:180 [inline]
dup_task_struct+0x57/0x8c0 kernel/fork.c:1107
copy_process+0x5d1/0x3d50 kernel/fork.c:2206
kernel_clone+0x223/0x880 kernel/fork.c:2787
kernel_thread+0x1bc/0x240 kernel/fork.c:2849
create_kthread kernel/kthread.c:412 [inline]
kthreadd+0x60d/0x810 kernel/kthread.c:765
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Freed by task 61:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
poison_slab_object mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_h
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix a NULL pointer dereference when failed to start a new trasacntion
[BUG]
Syzbot reported a NULL pointer dereference with the following crash:
FAULT_INJECTION: forcing a failure.
start_transaction+0x830/0x1670 fs/btrfs/transaction.c:676
prepare_to_relocate+0x31f/0x4c0 fs/btrfs/relocation.c:3642
relocate_block_group+0x169/0xd20 fs/btrfs/relocation.c:3678
...
BTRFS info (device loop0): balance: ended with status: -12
Oops: general protection fault, probably for non-canonical address 0xdffffc00000000cc: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000660-0x0000000000000667]
RIP: 0010:btrfs_update_reloc_root+0x362/0xa80 fs/btrfs/relocation.c:926
Call Trace:
<TASK>
commit_fs_roots+0x2ee/0x720 fs/btrfs/transaction.c:1496
btrfs_commit_transaction+0xfaf/0x3740 fs/btrfs/transaction.c:2430
del_balance_item fs/btrfs/volumes.c:3678 [inline]
reset_balance_state+0x25e/0x3c0 fs/btrfs/volumes.c:3742
btrfs_balance+0xead/0x10c0 fs/btrfs/volumes.c:4574
btrfs_ioctl_balance+0x493/0x7c0 fs/btrfs/ioctl.c:3673
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
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
[CAUSE]
The allocation failure happens at the start_transaction() inside
prepare_to_relocate(), and during the error handling we call
unset_reloc_control(), which makes fs_info->balance_ctl to be NULL.
Then we continue the error path cleanup in btrfs_balance() by calling
reset_balance_state() which will call del_balance_item() to fully delete
the balance item in the root tree.
However during the small window between set_reloc_contrl() and
unset_reloc_control(), we can have a subvolume tree update and created a
reloc_root for that subvolume.
Then we go into the final btrfs_commit_transaction() of
del_balance_item(), and into btrfs_update_reloc_root() inside
commit_fs_roots().
That function checks if fs_info->reloc_ctl is in the merge_reloc_tree
stage, but since fs_info->reloc_ctl is NULL, it results a NULL pointer
dereference.
[FIX]
Just add extra check on fs_info->reloc_ctl inside
btrfs_update_reloc_root(), before checking
fs_info->reloc_ctl->merge_reloc_tree.
That DEAD_RELOC_TREE handling is to prevent further modification to the
reloc tree during merge stage, but since there is no reloc_ctl at all,
we do not need to bother that.