| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
tee: fix register_shm_helper()
In register_shm_helper(), fix incorrect error handling for a call to
iov_iter_extract_pages(). A case is missing for when
iov_iter_extract_pages() only got some pages and return a number larger
than 0, but not the requested amount.
This fixes a possible NULL pointer dereference following a bad input from
ioctl(TEE_IOC_SHM_REGISTER) where parts of the buffer isn't mapped. |
| In the Linux kernel, the following vulnerability has been resolved:
hfsplus: Verify inode mode when loading from disk
syzbot is reporting that S_IFMT bits of inode->i_mode can become bogus when
the S_IFMT bits of the 16bits "mode" field loaded from disk are corrupted.
According to [1], the permissions field was treated as reserved in Mac OS
8 and 9. According to [2], the reserved field was explicitly initialized
with 0, and that field must remain 0 as long as reserved. Therefore, when
the "mode" field is not 0 (i.e. no longer reserved), the file must be
S_IFDIR if dir == 1, and the file must be one of S_IFREG/S_IFLNK/S_IFCHR/
S_IFBLK/S_IFIFO/S_IFSOCK if dir == 0. |
| In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix kernel BUG in ocfs2_find_victim_chain
syzbot reported a kernel BUG in ocfs2_find_victim_chain() because the
`cl_next_free_rec` field of the allocation chain list (next free slot in
the chain list) is 0, triggring the BUG_ON(!cl->cl_next_free_rec)
condition in ocfs2_find_victim_chain() and panicking the kernel.
To fix this, an if condition is introduced in ocfs2_claim_suballoc_bits(),
just before calling ocfs2_find_victim_chain(), the code block in it being
executed when either of the following conditions is true:
1. `cl_next_free_rec` is equal to 0, indicating that there are no free
chains in the allocation chain list
2. `cl_next_free_rec` is greater than `cl_count` (the total number of
chains in the allocation chain list)
Either of them being true is indicative of the fact that there are no
chains left for usage.
This is addressed using ocfs2_error(), which prints
the error log for debugging purposes, rather than panicking the kernel. |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid updating compression context during writeback
Bai, Shuangpeng <[email protected]> reported a bug as below:
Oops: divide error: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 11441 Comm: syz.0.46 Not tainted 6.17.0 #1 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:f2fs_all_cluster_page_ready+0x106/0x550 fs/f2fs/compress.c:857
Call Trace:
<TASK>
f2fs_write_cache_pages fs/f2fs/data.c:3078 [inline]
__f2fs_write_data_pages fs/f2fs/data.c:3290 [inline]
f2fs_write_data_pages+0x1c19/0x3600 fs/f2fs/data.c:3317
do_writepages+0x38e/0x640 mm/page-writeback.c:2634
filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
__filemap_fdatawrite_range mm/filemap.c:419 [inline]
file_write_and_wait_range+0x2ba/0x3e0 mm/filemap.c:794
f2fs_do_sync_file+0x6e6/0x1b00 fs/f2fs/file.c:294
generic_write_sync include/linux/fs.h:3043 [inline]
f2fs_file_write_iter+0x76e/0x2700 fs/f2fs/file.c:5259
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7e9/0xe00 fs/read_write.c:686
ksys_write+0x19d/0x2d0 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf7/0x470 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The bug was triggered w/ below race condition:
fsync setattr ioctl
- f2fs_do_sync_file
- file_write_and_wait_range
- f2fs_write_cache_pages
: inode is non-compressed
: cc.cluster_size =
F2FS_I(inode)->i_cluster_size = 0
- tag_pages_for_writeback
- f2fs_setattr
- truncate_setsize
- f2fs_truncate
- f2fs_fileattr_set
- f2fs_setflags_common
- set_compress_context
: F2FS_I(inode)->i_cluster_size = 4
: set_inode_flag(inode, FI_COMPRESSED_FILE)
- f2fs_compressed_file
: return true
- f2fs_all_cluster_page_ready
: "pgidx % cc->cluster_size" trigger dividing 0 issue
Let's change as below to fix this issue:
- introduce a new atomic type variable .writeback in structure f2fs_inode_info
to track the number of threads which calling f2fs_write_cache_pages().
- use .i_sem lock to protect .writeback update.
- check .writeback before update compression context in f2fs_setflags_common()
to avoid race w/ ->writepages. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: don't log conflicting inode if it's a dir moved in the current transaction
We can't log a conflicting inode if it's a directory and it was moved
from one parent directory to another parent directory in the current
transaction, as this can result an attempt to have a directory with
two hard links during log replay, one for the old parent directory and
another for the new parent directory.
The following scenario triggers that issue:
1) We have directories "dir1" and "dir2" created in a past transaction.
Directory "dir1" has inode A as its parent directory;
2) We move "dir1" to some other directory;
3) We create a file with the name "dir1" in directory inode A;
4) We fsync the new file. This results in logging the inode of the new file
and the inode for the directory "dir1" that was previously moved in the
current transaction. So the log tree has the INODE_REF item for the
new location of "dir1";
5) We move the new file to some other directory. This results in updating
the log tree to included the new INODE_REF for the new location of the
file and removes the INODE_REF for the old location. This happens
during the rename when we call btrfs_log_new_name();
6) We fsync the file, and that persists the log tree changes done in the
previous step (btrfs_log_new_name() only updates the log tree in
memory);
7) We have a power failure;
8) Next time the fs is mounted, log replay happens and when processing
the inode for directory "dir1" we find a new INODE_REF and add that
link, but we don't remove the old link of the inode since we have
not logged the old parent directory of the directory inode "dir1".
As a result after log replay finishes when we trigger writeback of the
subvolume tree's extent buffers, the tree check will detect that we have
a directory a hard link count of 2 and we get a mount failure.
The errors and stack traces reported in dmesg/syslog are like this:
[ 3845.729764] BTRFS info (device dm-0): start tree-log replay
[ 3845.730304] page: refcount:3 mapcount:0 mapping:000000005c8a3027 index:0x1d00 pfn:0x11510c
[ 3845.731236] memcg:ffff9264c02f4e00
[ 3845.731751] aops:btree_aops [btrfs] ino:1
[ 3845.732300] flags: 0x17fffc00000400a(uptodate|private|writeback|node=0|zone=2|lastcpupid=0x1ffff)
[ 3845.733346] raw: 017fffc00000400a 0000000000000000 dead000000000122 ffff9264d978aea8
[ 3845.734265] raw: 0000000000001d00 ffff92650e6d4738 00000003ffffffff ffff9264c02f4e00
[ 3845.735305] page dumped because: eb page dump
[ 3845.735981] BTRFS critical (device dm-0): corrupt leaf: root=5 block=30408704 slot=6 ino=257, invalid nlink: has 2 expect no more than 1 for dir
[ 3845.737786] BTRFS info (device dm-0): leaf 30408704 gen 10 total ptrs 17 free space 14881 owner 5
[ 3845.737789] BTRFS info (device dm-0): refs 4 lock_owner 0 current 30701
[ 3845.737792] item 0 key (256 INODE_ITEM 0) itemoff 16123 itemsize 160
[ 3845.737794] inode generation 3 transid 9 size 16 nbytes 16384
[ 3845.737795] block group 0 mode 40755 links 1 uid 0 gid 0
[ 3845.737797] rdev 0 sequence 2 flags 0x0
[ 3845.737798] atime 1764259517.0
[ 3845.737800] ctime 1764259517.572889464
[ 3845.737801] mtime 1764259517.572889464
[ 3845.737802] otime 1764259517.0
[ 3845.737803] item 1 key (256 INODE_REF 256) itemoff 16111 itemsize 12
[ 3845.737805] index 0 name_len 2
[ 3845.737807] item 2 key (256 DIR_ITEM 2363071922) itemoff 16077 itemsize 34
[ 3845.737808] location key (257 1 0) type 2
[ 3845.737810] transid 9 data_len 0 name_len 4
[ 3845.737811] item 3 key (256 DIR_ITEM 2676584006) itemoff 16043 itemsize 34
[ 3845.737813] location key (258 1 0) type 2
[ 3845.737814] transid 9 data_len 0 name_len 4
[ 3845.737815] item 4 key (256 DIR_INDEX 2) itemoff 16009 itemsize 34
[ 3845.737816] location key (257 1 0) type 2
[
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid migrating empty section
It reports a bug from device w/ zufs:
F2FS-fs (dm-64): Inconsistent segment (173822) type [1, 0] in SSA and SIT
F2FS-fs (dm-64): Stopped filesystem due to reason: 4
Thread A Thread B
- f2fs_expand_inode_data
- f2fs_allocate_pinning_section
- f2fs_gc_range
- do_garbage_collect w/ segno #x
- writepage
- f2fs_allocate_data_block
- new_curseg
- allocate segno #x
The root cause is: fallocate on pinning file may race w/ block allocation
as above, result in do_garbage_collect() from fallocate() may migrate
segment which is just allocated by a log, the log will update segment type
in its in-memory structure, however GC will get segment type from on-disk
SSA block, once segment type changes by log, we can detect such
inconsistency, then shutdown filesystem.
In this case, on-disk SSA shows type of segno #173822 is 1 (SUM_TYPE_NODE),
however segno #173822 was just allocated as data type segment, so in-memory
SIT shows type of segno #173822 is 0 (SUM_TYPE_DATA).
Change as below to fix this issue:
- check whether current section is empty before gc
- add sanity checks on do_garbage_collect() to avoid any race case, result
in migrating segment used by log.
- btw, it fixes misc issue in printed logs: "SSA and SIT" -> "SIT and SSA". |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Avoid unregistering PSP twice
PSP is unregistered twice in:
_mlx5e_remove -> mlx5e_psp_unregister
mlx5e_nic_cleanup -> mlx5e_psp_unregister
This leads to a refcount underflow in some conditions:
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 2 PID: 1694 at lib/refcount.c:28 refcount_warn_saturate+0xd8/0xe0
[...]
mlx5e_psp_unregister+0x26/0x50 [mlx5_core]
mlx5e_nic_cleanup+0x26/0x90 [mlx5_core]
mlx5e_remove+0xe6/0x1f0 [mlx5_core]
auxiliary_bus_remove+0x18/0x30
device_release_driver_internal+0x194/0x1f0
bus_remove_device+0xc6/0x130
device_del+0x159/0x3c0
mlx5_rescan_drivers_locked+0xbc/0x2a0 [mlx5_core]
[...]
Do not directly remove psp from the _mlx5e_remove path, the PSP cleanup
happens as part of profile cleanup. |
| In the Linux kernel, the following vulnerability has been resolved:
sched/deadline: only set free_cpus for online runqueues
Commit 16b269436b72 ("sched/deadline: Modify cpudl::free_cpus
to reflect rd->online") introduced the cpudl_set/clear_freecpu
functions to allow the cpu_dl::free_cpus mask to be manipulated
by the deadline scheduler class rq_on/offline callbacks so the
mask would also reflect this state.
Commit 9659e1eeee28 ("sched/deadline: Remove cpu_active_mask
from cpudl_find()") removed the check of the cpu_active_mask to
save some processing on the premise that the cpudl::free_cpus
mask already reflected the runqueue online state.
Unfortunately, there are cases where it is possible for the
cpudl_clear function to set the free_cpus bit for a CPU when the
deadline runqueue is offline. When this occurs while a CPU is
connected to the default root domain the flag may retain the bad
state after the CPU has been unplugged. Later, a different CPU
that is transitioning through the default root domain may push a
deadline task to the powered down CPU when cpudl_find sees its
free_cpus bit is set. If this happens the task will not have the
opportunity to run.
One example is outlined here:
https://lore.kernel.org/lkml/[email protected]
Another occurs when the last deadline task is migrated from a
CPU that has an offlined runqueue. The dequeue_task member of
the deadline scheduler class will eventually call cpudl_clear
and set the free_cpus bit for the CPU.
This commit modifies the cpudl_clear function to be aware of the
online state of the deadline runqueue so that the free_cpus mask
can be updated appropriately.
It is no longer necessary to manage the mask outside of the
cpudl_set/clear functions so the cpudl_set/clear_freecpu
functions are removed. In addition, since the free_cpus mask is
now only updated under the cpudl lock the code was changed to
use the non-atomic __cpumask functions. |
| In the Linux kernel, the following vulnerability has been resolved:
usb: phy: fsl-usb: Fix use-after-free in delayed work during device removal
The delayed work item otg_event is initialized in fsl_otg_conf() and
scheduled under two conditions:
1. When a host controller binds to the OTG controller.
2. When the USB ID pin state changes (cable insertion/removal).
A race condition occurs when the device is removed via fsl_otg_remove():
the fsl_otg instance may be freed while the delayed work is still pending
or executing. This leads to use-after-free when the work function
fsl_otg_event() accesses the already freed memory.
The problematic scenario:
(detach thread) | (delayed work)
fsl_otg_remove() |
kfree(fsl_otg_dev) //FREE| fsl_otg_event()
| og = container_of(...) //USE
| og-> //USE
Fix this by calling disable_delayed_work_sync() in fsl_otg_remove()
before deallocating the fsl_otg structure. This ensures the delayed work
is properly canceled and completes execution prior to memory deallocation.
This bug was identified through static analysis. |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: fix a UAF problem in xattr repair
The xchk_setup_xattr_buf function can allocate a new value buffer, which
means that any reference to ab->value before the call could become a
dangling pointer. Fix this by moving an assignment to after the buffer
setup. |
| In the Linux kernel, the following vulnerability has been resolved:
netrom: Fix memory leak in nr_sendmsg()
syzbot reported a memory leak [1].
When function sock_alloc_send_skb() return NULL in nr_output(), the
original skb is not freed, which was allocated in nr_sendmsg(). Fix this
by freeing it before return.
[1]
BUG: memory leak
unreferenced object 0xffff888129f35500 (size 240):
comm "syz.0.17", pid 6119, jiffies 4294944652
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 10 52 28 81 88 ff ff ..........R(....
backtrace (crc 1456a3e4):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4983 [inline]
slab_alloc_node mm/slub.c:5288 [inline]
kmem_cache_alloc_node_noprof+0x36f/0x5e0 mm/slub.c:5340
__alloc_skb+0x203/0x240 net/core/skbuff.c:660
alloc_skb include/linux/skbuff.h:1383 [inline]
alloc_skb_with_frags+0x69/0x3f0 net/core/skbuff.c:6671
sock_alloc_send_pskb+0x379/0x3e0 net/core/sock.c:2965
sock_alloc_send_skb include/net/sock.h:1859 [inline]
nr_sendmsg+0x287/0x450 net/netrom/af_netrom.c:1105
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
sock_write_iter+0x293/0x2a0 net/socket.c:1195
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x45d/0x710 fs/read_write.c:686
ksys_write+0x143/0x170 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f |
| In the Linux kernel, the following vulnerability has been resolved:
MIPS: fw: Allow firmware to pass a empty env
fw_getenv will use env entry to determine style of env,
however it is legal for firmware to just pass a empty list.
Check if first entry exist before running strchr to avoid
null pointer dereference. |
| In the Linux kernel, the following vulnerability has been resolved:
fuse: missing copy_finish in fuse-over-io-uring argument copies
Fix a possible reference count leak of payload pages during
fuse argument copies.
[Joanne: simplified error cleanup] |
| In the Linux kernel, the following vulnerability has been resolved:
perf/x86/amd: Check event before enable to avoid GPF
On AMD machines cpuc->events[idx] can become NULL in a subtle race
condition with NMI->throttle->x86_pmu_stop().
Check event for NULL in amd_pmu_enable_all() before enable to avoid a GPF.
This appears to be an AMD only issue.
Syzkaller reported a GPF in amd_pmu_enable_all.
INFO: NMI handler (perf_event_nmi_handler) took too long to run: 13.143
msecs
Oops: general protection fault, probably for non-canonical address
0xdffffc0000000034: 0000 PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x00000000000001a0-0x00000000000001a7]
CPU: 0 UID: 0 PID: 328415 Comm: repro_36674776 Not tainted 6.12.0-rc1-syzk
RIP: 0010:x86_pmu_enable_event (arch/x86/events/perf_event.h:1195
arch/x86/events/core.c:1430)
RSP: 0018:ffff888118009d60 EFLAGS: 00010012
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000034 RSI: 0000000000000000 RDI: 00000000000001a0
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: ffff88811802a440 R14: ffff88811802a240 R15: ffff8881132d8601
FS: 00007f097dfaa700(0000) GS:ffff888118000000(0000) GS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200001c0 CR3: 0000000103d56000 CR4: 00000000000006f0
Call Trace:
<IRQ>
amd_pmu_enable_all (arch/x86/events/amd/core.c:760 (discriminator 2))
x86_pmu_enable (arch/x86/events/core.c:1360)
event_sched_out (kernel/events/core.c:1191 kernel/events/core.c:1186
kernel/events/core.c:2346)
__perf_remove_from_context (kernel/events/core.c:2435)
event_function (kernel/events/core.c:259)
remote_function (kernel/events/core.c:92 (discriminator 1)
kernel/events/core.c:72 (discriminator 1))
__flush_smp_call_function_queue (./arch/x86/include/asm/jump_label.h:27
./include/linux/jump_label.h:207 ./include/trace/events/csd.h:64
kernel/smp.c:135 kernel/smp.c:540)
__sysvec_call_function_single (./arch/x86/include/asm/jump_label.h:27
./include/linux/jump_label.h:207
./arch/x86/include/asm/trace/irq_vectors.h:99 arch/x86/kernel/smp.c:272)
sysvec_call_function_single (arch/x86/kernel/smp.c:266 (discriminator 47)
arch/x86/kernel/smp.c:266 (discriminator 47))
</IRQ> |
| In the Linux kernel, the following vulnerability has been resolved:
block: fix race between wbt_enable_default and IO submission
When wbt_enable_default() is moved out of queue freezing in elevator_change(),
it can cause the wbt inflight counter to become negative (-1), leading to hung
tasks in the writeback path. Tasks get stuck in wbt_wait() because the counter
is in an inconsistent state.
The issue occurs because wbt_enable_default() could race with IO submission,
allowing the counter to be decremented before proper initialization. This manifests
as:
rq_wait[0]:
inflight: -1
has_waiters: True
rwb_enabled() checks the state, which can be updated exactly between wbt_wait()
(rq_qos_throttle()) and wbt_track()(rq_qos_track()), then the inflight counter
will become negative.
And results in hung task warnings like:
task:kworker/u24:39 state:D stack:0 pid:14767
Call Trace:
rq_qos_wait+0xb4/0x150
wbt_wait+0xa9/0x100
__rq_qos_throttle+0x24/0x40
blk_mq_submit_bio+0x672/0x7b0
...
Fix this by:
1. Splitting wbt_enable_default() into:
- __wbt_enable_default(): Returns true if wbt_init() should be called
- wbt_enable_default(): Wrapper for existing callers (no init)
- wbt_init_enable_default(): New function that checks and inits WBT
2. Using wbt_init_enable_default() in blk_register_queue() to ensure
proper initialization during queue registration
3. Move wbt_init() out of wbt_enable_default() which is only for enabling
disabled wbt from bfq and iocost, and wbt_init() isn't needed. Then the
original lock warning can be avoided.
4. Removing the ELEVATOR_FLAG_ENABLE_WBT_ON_EXIT flag and its handling
code since it's no longer needed
This ensures WBT is properly initialized before any IO can be submitted,
preventing the counter from going negative. |
| In the Linux kernel, the following vulnerability has been resolved:
media: imon: make send_packet() more robust
syzbot is reporting that imon has three problems which result in
hung tasks due to forever holding device lock [1].
First problem is that when usb_rx_callback_intf0() once got -EPROTO error
after ictx->dev_present_intf0 became true, usb_rx_callback_intf0()
resubmits urb after printk(), and resubmitted urb causes
usb_rx_callback_intf0() to again get -EPROTO error. This results in
printk() flooding (RCU stalls).
Alan Stern commented [2] that
In theory it's okay to resubmit _if_ the driver has a robust
error-recovery scheme (such as giving up after some fixed limit on the
number of errors or after some fixed time has elapsed, perhaps with a
time delay to prevent a flood of errors). Most drivers don't bother to
do this; they simply give up right away. This makes them more
vulnerable to short-term noise interference during USB transfers, but in
reality such interference is quite rare. There's nothing really wrong
with giving up right away.
but imon has a poor error-recovery scheme which just retries forever;
this behavior should be fixed.
Since I'm not sure whether it is safe for imon users to give up upon any
error code, this patch takes care of only union of error codes chosen from
modules in drivers/media/rc/ directory which handle -EPROTO error (i.e.
ir_toy, mceusb and igorplugusb).
Second problem is that when usb_rx_callback_intf0() once got -EPROTO error
before ictx->dev_present_intf0 becomes true, usb_rx_callback_intf0() always
resubmits urb due to commit 8791d63af0cf ("[media] imon: don't wedge
hardware after early callbacks"). Move the ictx->dev_present_intf0 test
introduced by commit 6f6b90c9231a ("[media] imon: don't parse scancodes
until intf configured") to immediately before imon_incoming_packet(), or
the first problem explained above happens without printk() flooding (i.e.
hung task).
Third problem is that when usb_rx_callback_intf0() is not called for some
reason (e.g. flaky hardware; the reproducer for this problem sometimes
prevents usb_rx_callback_intf0() from being called),
wait_for_completion_interruptible() in send_packet() never returns (i.e.
hung task). As a workaround for such situation, change send_packet() to
wait for completion with timeout of 10 seconds. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring: fix filename leak in __io_openat_prep()
__io_openat_prep() allocates a struct filename using getname(). However,
for the condition of the file being installed in the fixed file table as
well as having O_CLOEXEC flag set, the function returns early. At that
point, the request doesn't have REQ_F_NEED_CLEANUP flag set. Due to this,
the memory for the newly allocated struct filename is not cleaned up,
causing a memory leak.
Fix this by setting the REQ_F_NEED_CLEANUP for the request just after the
successful getname() call, so that when the request is torn down, the
filename will be cleaned up, along with other resources needing cleanup. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdkfd: Add missing gfx11 MQD manager callbacks
mqd_stride function was introduced in commit 2f77b9a242a2
("drm/amdkfd: Update MQD management on multi XCC setup")
but not assigned for gfx11. Fixes a NULL dereference in debugfs. |
| In the Linux kernel, the following vulnerability has been resolved:
fuse: fix readahead reclaim deadlock
Commit e26ee4efbc79 ("fuse: allocate ff->release_args only if release is
needed") skips allocating ff->release_args if the server does not
implement open. However in doing so, fuse_prepare_release() now skips
grabbing the reference on the inode, which makes it possible for an
inode to be evicted from the dcache while there are inflight readahead
requests. This causes a deadlock if the server triggers reclaim while
servicing the readahead request and reclaim attempts to evict the inode
of the file being read ahead. Since the folio is locked during
readahead, when reclaim evicts the fuse inode and fuse_evict_inode()
attempts to remove all folios associated with the inode from the page
cache (truncate_inode_pages_range()), reclaim will block forever waiting
for the lock since readahead cannot relinquish the lock because it is
itself blocked in reclaim:
>>> stack_trace(1504735)
folio_wait_bit_common (mm/filemap.c:1308:4)
folio_lock (./include/linux/pagemap.h:1052:3)
truncate_inode_pages_range (mm/truncate.c:336:10)
fuse_evict_inode (fs/fuse/inode.c:161:2)
evict (fs/inode.c:704:3)
dentry_unlink_inode (fs/dcache.c:412:3)
__dentry_kill (fs/dcache.c:615:3)
shrink_kill (fs/dcache.c:1060:12)
shrink_dentry_list (fs/dcache.c:1087:3)
prune_dcache_sb (fs/dcache.c:1168:2)
super_cache_scan (fs/super.c:221:10)
do_shrink_slab (mm/shrinker.c:435:9)
shrink_slab (mm/shrinker.c:626:10)
shrink_node (mm/vmscan.c:5951:2)
shrink_zones (mm/vmscan.c:6195:3)
do_try_to_free_pages (mm/vmscan.c:6257:3)
do_swap_page (mm/memory.c:4136:11)
handle_pte_fault (mm/memory.c:5562:10)
handle_mm_fault (mm/memory.c:5870:9)
do_user_addr_fault (arch/x86/mm/fault.c:1338:10)
handle_page_fault (arch/x86/mm/fault.c:1481:3)
exc_page_fault (arch/x86/mm/fault.c:1539:2)
asm_exc_page_fault+0x22/0x27
Fix this deadlock by allocating ff->release_args and grabbing the
reference on the inode when preparing the file for release even if the
server does not implement open. The inode reference will be dropped when
the last reference on the fuse file is dropped (see fuse_file_put() ->
fuse_release_end()). |
| In the Linux kernel, the following vulnerability has been resolved:
ntfs: set dummy blocksize to read boot_block when mounting
When mounting, sb->s_blocksize is used to read the boot_block without
being defined or validated. Set a dummy blocksize before attempting to
read the boot_block.
The issue can be triggered with the following syz reproducer:
mkdirat(0xffffffffffffff9c, &(0x7f0000000080)='./file1\x00', 0x0)
r4 = openat$nullb(0xffffffffffffff9c, &(0x7f0000000040), 0x121403, 0x0)
ioctl$FS_IOC_SETFLAGS(r4, 0x40081271, &(0x7f0000000980)=0x4000)
mount(&(0x7f0000000140)=@nullb, &(0x7f0000000040)='./cgroup\x00',
&(0x7f0000000000)='ntfs3\x00', 0x2208004, 0x0)
syz_clone(0x88200200, 0x0, 0x0, 0x0, 0x0, 0x0)
Here, the ioctl sets the bdev block size to 16384. During mount,
get_tree_bdev_flags() calls sb_set_blocksize(sb, block_size(bdev)),
but since block_size(bdev) > PAGE_SIZE, sb_set_blocksize() leaves
sb->s_blocksize at zero.
Later, ntfs_init_from_boot() attempts to read the boot_block while
sb->s_blocksize is still zero, which triggers the bug.
[[email protected]: changed comment style, added
return value handling] |
