In the Linux kernel, the following vulnerability has been resolved:
jbd2: remove wrong sb->s_sequence check
Journal emptiness is not determined by sb->s_sequence == 0 but rather by
sb->s_start == 0 (which is set a few lines above). Furthermore 0 is a
valid transaction ID so the check can spuriously trigger. Remove the
invalid WARN_ON.
In the Linux kernel, the following vulnerability has been resolved:
pm: cpupower: bench: Prevent NULL dereference on malloc failure
If malloc returns NULL due to low memory, 'config' pointer can be NULL.
Add a check to prevent NULL dereference.
In the Linux kernel, the following vulnerability has been resolved:
mm/vmscan: don't try to reclaim hwpoison folio
Syzkaller reports a bug as follows:
Injecting memory failure for pfn 0x18b00e at process virtual address 0x20ffd000
Memory failure: 0x18b00e: dirty swapcache page still referenced by 2 users
Memory failure: 0x18b00e: recovery action for dirty swapcache page: Failed
page: refcount:2 mapcount:0 mapping:0000000000000000 index:0x20ffd pfn:0x18b00e
memcg:ffff0000dd6d9000
anon flags: 0x5ffffe00482011(locked|dirty|arch_1|swapbacked|hwpoison|node=0|zone=2|lastcpupid=0xfffff)
raw: 005ffffe00482011 dead000000000100 dead000000000122 ffff0000e232a7c9
raw: 0000000000020ffd 0000000000000000 00000002ffffffff ffff0000dd6d9000
page dumped because: VM_BUG_ON_FOLIO(!folio_test_uptodate(folio))
------------[ cut here ]------------
kernel BUG at mm/swap_state.c:184!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
Modules linked in:
CPU: 0 PID: 60 Comm: kswapd0 Not tainted 6.6.0-gcb097e7de84e #3
Hardware name: linux,dummy-virt (DT)
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : add_to_swap+0xbc/0x158
lr : add_to_swap+0xbc/0x158
sp : ffff800087f37340
x29: ffff800087f37340 x28: fffffc00052c0380 x27: ffff800087f37780
x26: ffff800087f37490 x25: ffff800087f37c78 x24: ffff800087f377a0
x23: ffff800087f37c50 x22: 0000000000000000 x21: fffffc00052c03b4
x20: 0000000000000000 x19: fffffc00052c0380 x18: 0000000000000000
x17: 296f696c6f662865 x16: 7461646f7470755f x15: 747365745f6f696c
x14: 6f6621284f494c4f x13: 0000000000000001 x12: ffff600036d8b97b
x11: 1fffe00036d8b97a x10: ffff600036d8b97a x9 : dfff800000000000
x8 : 00009fffc9274686 x7 : ffff0001b6c5cbd3 x6 : 0000000000000001
x5 : ffff0000c25896c0 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : ffff0000c25896c0 x0 : 0000000000000000
Call trace:
add_to_swap+0xbc/0x158
shrink_folio_list+0x12ac/0x2648
shrink_inactive_list+0x318/0x948
shrink_lruvec+0x450/0x720
shrink_node_memcgs+0x280/0x4a8
shrink_node+0x128/0x978
balance_pgdat+0x4f0/0xb20
kswapd+0x228/0x438
kthread+0x214/0x230
ret_from_fork+0x10/0x20
I can reproduce this issue with the following steps:
1) When a dirty swapcache page is isolated by reclaim process and the
page isn't locked, inject memory failure for the page.
me_swapcache_dirty() clears uptodate flag and tries to delete from lru,
but fails. Reclaim process will put the hwpoisoned page back to lru.
2) The process that maps the hwpoisoned page exits, the page is deleted
the page will never be freed and will be in the lru forever.
3) If we trigger a reclaim again and tries to reclaim the page,
add_to_swap() will trigger VM_BUG_ON_FOLIO due to the uptodate flag is
cleared.
To fix it, skip the hwpoisoned page in shrink_folio_list(). Besides, the
hwpoison folio may not be unmapped by hwpoison_user_mappings() yet, unmap
it in shrink_folio_list(), otherwise the folio will fail to be unmaped by
hwpoison_user_mappings() since the folio isn't in lru list.
In the Linux kernel, the following vulnerability has been resolved:
spi: spi-imx: Add check for spi_imx_setupxfer()
Add check for the return value of spi_imx_setupxfer().
spi_imx->rx and spi_imx->tx function pointer can be NULL when
spi_imx_setupxfer() return error, and make NULL pointer dereference.
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Call trace:
0x0
spi_imx_pio_transfer+0x50/0xd8
spi_imx_transfer_one+0x18c/0x858
spi_transfer_one_message+0x43c/0x790
__spi_pump_transfer_message+0x238/0x5d4
__spi_sync+0x2b0/0x454
spi_write_then_read+0x11c/0x200
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix WARNING "do not call blocking ops when !TASK_RUNNING"
wait_event_timeout() will set the state of the current
task to TASK_UNINTERRUPTIBLE, before doing the condition check. This
means that ksmbd_durable_scavenger_alive() will try to acquire the mutex
while already in a sleeping state. The scheduler warns us by giving
the following warning:
do not call blocking ops when !TASK_RUNNING; state=2 set at
[<0000000061515a6f>] prepare_to_wait_event+0x9f/0x6c0
WARNING: CPU: 2 PID: 4147 at kernel/sched/core.c:10099 __might_sleep+0x12f/0x160
mutex lock is not needed in ksmbd_durable_scavenger_alive().
In the Linux kernel, the following vulnerability has been resolved:
udmabuf: fix a buf size overflow issue during udmabuf creation
by casting size_limit_mb to u64 when calculate pglimit.
In the Linux kernel, the following vulnerability has been resolved:
sound/virtio: Fix cancel_sync warnings on uninitialized work_structs
Betty reported hitting the following warning:
[ 8.709131][ T221] WARNING: CPU: 2 PID: 221 at kernel/workqueue.c:4182
...
[ 8.713282][ T221] Call trace:
[ 8.713365][ T221] __flush_work+0x8d0/0x914
[ 8.713468][ T221] __cancel_work_sync+0xac/0xfc
[ 8.713570][ T221] cancel_work_sync+0x24/0x34
[ 8.713667][ T221] virtsnd_remove+0xa8/0xf8 [virtio_snd ab15f34d0dd772f6d11327e08a81d46dc9c36276]
[ 8.713868][ T221] virtsnd_probe+0x48c/0x664 [virtio_snd ab15f34d0dd772f6d11327e08a81d46dc9c36276]
[ 8.714035][ T221] virtio_dev_probe+0x28c/0x390
[ 8.714139][ T221] really_probe+0x1bc/0x4c8
...
It seems we're hitting the error path in virtsnd_probe(), which
triggers a virtsnd_remove() which iterates over the substreams
calling cancel_work_sync() on the elapsed_period work_struct.
Looking at the code, from earlier in:
virtsnd_probe()->virtsnd_build_devs()->virtsnd_pcm_parse_cfg()
We set snd->nsubstreams, allocate the snd->substreams, and if
we then hit an error on the info allocation or something in
virtsnd_ctl_query_info() fails, we will exit without having
initialized the elapsed_period work_struct.
When that error path unwinds we then call virtsnd_remove()
which as long as the substreams array is allocated, will iterate
through calling cancel_work_sync() on the uninitialized work
struct hitting this warning.
Takashi Iwai suggested this fix, which initializes the substreams
structure right after allocation, so that if we hit the error
paths we avoid trying to cleanup uninitialized data.
Note: I have not yet managed to reproduce the issue myself, so
this patch has had limited testing.
Feedback or thoughts would be appreciated!
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix kmemleak warning for percpu hashmap
Vlad Poenaru reported the following kmemleak issue:
unreferenced object 0x606fd7c44ac8 (size 32):
backtrace (crc 0):
pcpu_alloc_noprof+0x730/0xeb0
bpf_map_alloc_percpu+0x69/0xc0
prealloc_init+0x9d/0x1b0
htab_map_alloc+0x363/0x510
map_create+0x215/0x3a0
__sys_bpf+0x16b/0x3e0
__x64_sys_bpf+0x18/0x20
do_syscall_64+0x7b/0x150
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Further investigation shows the reason is due to not 8-byte aligned
store of percpu pointer in htab_elem_set_ptr():
*(void __percpu **)(l->key + key_size) = pptr;
Note that the whole htab_elem alignment is 8 (for x86_64). If the key_size
is 4, that means pptr is stored in a location which is 4 byte aligned but
not 8 byte aligned. In mm/kmemleak.c, scan_block() scans the memory based
on 8 byte stride, so it won't detect above pptr, hence reporting the memory
leak.
In htab_map_alloc(), we already have
htab->elem_size = sizeof(struct htab_elem) +
round_up(htab->map.key_size, 8);
if (percpu)
htab->elem_size += sizeof(void *);
else
htab->elem_size += round_up(htab->map.value_size, 8);
So storing pptr with 8-byte alignment won't cause any problem and can fix
kmemleak too.
The issue can be reproduced with bpf selftest as well:
1. Enable CONFIG_DEBUG_KMEMLEAK config
2. Add a getchar() before skel destroy in test_hash_map() in prog_tests/for_each.c.
The purpose is to keep map available so kmemleak can be detected.
3. run './test_progs -t for_each/hash_map &' and a kmemleak should be reported.
In the Linux kernel, the following vulnerability has been resolved:
driver core: fix potential NULL pointer dereference in dev_uevent()
If userspace reads "uevent" device attribute at the same time as another
threads unbinds the device from its driver, change to dev->driver from a
valid pointer to NULL may result in crash. Fix this by using READ_ONCE()
when fetching the pointer, and take bus' drivers klist lock to make sure
driver instance will not disappear while we access it.
Use WRITE_ONCE() when setting the driver pointer to ensure there is no
tearing.
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: Fix WRITE_SAME No Data Buffer crash
In newer version of the SBC specs, we have a NDOB bit that indicates there
is no data buffer that gets written out. If this bit is set using commands
like "sg_write_same --ndob" we will crash in target_core_iblock/file's
execute_write_same handlers when we go to access the se_cmd->t_data_sg
because its NULL.
This patch adds a check for the NDOB bit in the common WRITE SAME code
because we don't support it. And, it adds a check for zero SG elements in
each handler in case the initiator tries to send a normal WRITE SAME with
no data buffer.