In the Linux kernel, the following vulnerability has been resolved:
drm/dp_mst: Fix MST sideband message body length check
Fix the MST sideband message body length check, which must be at least 1
byte accounting for the message body CRC (aka message data CRC) at the
end of the message.
This fixes a case where an MST branch device returns a header with a
correct header CRC (indicating a correctly received body length), with
the body length being incorrectly set to 0. This will later lead to a
memory corruption in drm_dp_sideband_append_payload() and the following
errors in dmesg:
UBSAN: array-index-out-of-bounds in drivers/gpu/drm/display/drm_dp_mst_topology.c:786:25
index -1 is out of range for type 'u8 [48]'
Call Trace:
drm_dp_sideband_append_payload+0x33d/0x350 [drm_display_helper]
drm_dp_get_one_sb_msg+0x3ce/0x5f0 [drm_display_helper]
drm_dp_mst_hpd_irq_handle_event+0xc8/0x1580 [drm_display_helper]
memcpy: detected field-spanning write (size 18446744073709551615) of single field "&msg->msg[msg->curlen]" at drivers/gpu/drm/display/drm_dp_mst_topology.c:791 (size 256)
Call Trace:
drm_dp_sideband_append_payload+0x324/0x350 [drm_display_helper]
drm_dp_get_one_sb_msg+0x3ce/0x5f0 [drm_display_helper]
drm_dp_mst_hpd_irq_handle_event+0xc8/0x1580 [drm_display_helper]
In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix potential out-of-bounds memory access in nilfs_find_entry()
Syzbot reported that when searching for records in a directory where the
inode's i_size is corrupted and has a large value, memory access outside
the folio/page range may occur, or a use-after-free bug may be detected if
KASAN is enabled.
This is because nilfs_last_byte(), which is called by nilfs_find_entry()
and others to calculate the number of valid bytes of directory data in a
page from i_size and the page index, loses the upper 32 bits of the 64-bit
size information due to an inappropriate type of local variable to which
the i_size value is assigned.
This caused a large byte offset value due to underflow in the end address
calculation in the calling nilfs_find_entry(), resulting in memory access
that exceeds the folio/page size.
Fix this issue by changing the type of the local variable causing the bit
loss from "unsigned int" to "u64". The return value of nilfs_last_byte()
is also of type "unsigned int", but it is truncated so as not to exceed
PAGE_SIZE and no bit loss occurs, so no change is required.
In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: core: sysfs: Prevent div by zero
Prevent a division by 0 when monitoring is not enabled.
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla2xxx: Fix use after free on unload
System crash is observed with stack trace warning of use after
free. There are 2 signals to tell dpc_thread to terminate (UNLOADING
flag and kthread_stop).
On setting the UNLOADING flag when dpc_thread happens to run at the time
and sees the flag, this causes dpc_thread to exit and clean up
itself. When kthread_stop is called for final cleanup, this causes use
after free.
Remove UNLOADING signal to terminate dpc_thread. Use the kthread_stop
as the main signal to exit dpc_thread.
[596663.812935] kernel BUG at mm/slub.c:294!
[596663.812950] invalid opcode: 0000 [#1] SMP PTI
[596663.812957] CPU: 13 PID: 1475935 Comm: rmmod Kdump: loaded Tainted: G IOE --------- - - 4.18.0-240.el8.x86_64 #1
[596663.812960] Hardware name: HP ProLiant DL380p Gen8, BIOS P70 08/20/2012
[596663.812974] RIP: 0010:__slab_free+0x17d/0x360
...
[596663.813008] Call Trace:
[596663.813022] ? __dentry_kill+0x121/0x170
[596663.813030] ? _cond_resched+0x15/0x30
[596663.813034] ? _cond_resched+0x15/0x30
[596663.813039] ? wait_for_completion+0x35/0x190
[596663.813048] ? try_to_wake_up+0x63/0x540
[596663.813055] free_task+0x5a/0x60
[596663.813061] kthread_stop+0xf3/0x100
[596663.813103] qla2x00_remove_one+0x284/0x440 [qla2xxx]
In the Linux kernel, the following vulnerability has been resolved:
af_packet: avoid erroring out after sock_init_data() in packet_create()
After sock_init_data() the allocated sk object is attached to the provided
sock object. On error, packet_create() frees the sk object leaving the
dangling pointer in the sock object on return. Some other code may try
to use this pointer and cause use-after-free.
In the Linux kernel, the following vulnerability has been resolved:
kcsan: Turn report_filterlist_lock into a raw_spinlock
Ran Xiaokai reports that with a KCSAN-enabled PREEMPT_RT kernel, we can see
splats like:
| BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48
| in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1
| preempt_count: 10002, expected: 0
| RCU nest depth: 0, expected: 0
| no locks held by swapper/1/0.
| irq event stamp: 156674
| hardirqs last enabled at (156673): [<ffffffff81130bd9>] do_idle+0x1f9/0x240
| hardirqs last disabled at (156674): [<ffffffff82254f84>] sysvec_apic_timer_interrupt+0x14/0xc0
| softirqs last enabled at (0): [<ffffffff81099f47>] copy_process+0xfc7/0x4b60
| softirqs last disabled at (0): [<0000000000000000>] 0x0
| Preemption disabled at:
| [<ffffffff814a3e2a>] paint_ptr+0x2a/0x90
| CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.11.0+ #3
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
| Call Trace:
| <IRQ>
| dump_stack_lvl+0x7e/0xc0
| dump_stack+0x1d/0x30
| __might_resched+0x1a2/0x270
| rt_spin_lock+0x68/0x170
| kcsan_skip_report_debugfs+0x43/0xe0
| print_report+0xb5/0x590
| kcsan_report_known_origin+0x1b1/0x1d0
| kcsan_setup_watchpoint+0x348/0x650
| __tsan_unaligned_write1+0x16d/0x1d0
| hrtimer_interrupt+0x3d6/0x430
| __sysvec_apic_timer_interrupt+0xe8/0x3a0
| sysvec_apic_timer_interrupt+0x97/0xc0
| </IRQ>
On a detected data race, KCSAN's reporting logic checks if it should
filter the report. That list is protected by the report_filterlist_lock
*non-raw* spinlock which may sleep on RT kernels.
Since KCSAN may report data races in any context, convert it to a
raw_spinlock.
This requires being careful about when to allocate memory for the filter
list itself which can be done via KCSAN's debugfs interface. Concurrent
modification of the filter list via debugfs should be rare: the chosen
strategy is to optimistically pre-allocate memory before the critical
section and discard if unused.
In the Linux kernel, the following vulnerability has been resolved:
mm/mempolicy: fix migrate_to_node() assuming there is at least one VMA in a MM
We currently assume that there is at least one VMA in a MM, which isn't
true.
So we might end up having find_vma() return NULL, to then de-reference
NULL. So properly handle find_vma() returning NULL.
This fixes the report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 6021 Comm: syz-executor284 Not tainted 6.12.0-rc7-syzkaller-00187-gf868cd251776 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0010:migrate_to_node mm/mempolicy.c:1090 [inline]
RIP: 0010:do_migrate_pages+0x403/0x6f0 mm/mempolicy.c:1194
Code: ...
RSP: 0018:ffffc9000375fd08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffc9000375fd78 RCX: 0000000000000000
RDX: ffff88807e171300 RSI: dffffc0000000000 RDI: ffff88803390c044
RBP: ffff88807e171428 R08: 0000000000000014 R09: fffffbfff2039ef1
R10: ffffffff901cf78f R11: 0000000000000000 R12: 0000000000000003
R13: ffffc9000375fe90 R14: ffffc9000375fe98 R15: ffffc9000375fdf8
FS: 00005555919e1380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555919e1ca8 CR3: 000000007f12a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
kernel_migrate_pages+0x5b2/0x750 mm/mempolicy.c:1709
__do_sys_migrate_pages mm/mempolicy.c:1727 [inline]
__se_sys_migrate_pages mm/mempolicy.c:1723 [inline]
__x64_sys_migrate_pages+0x96/0x100 mm/mempolicy.c:1723
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[akpm@linux-foundation.org: add unlikely()]