In the Linux kernel, the following vulnerability has been resolved:
jfs: Prevent copying of nlink with value 0 from disk inode
syzbot report a deadlock in diFree. [1]
When calling "ioctl$LOOP_SET_STATUS64", the offset value passed in is 4,
which does not match the mounted loop device, causing the mapping of the
mounted loop device to be invalidated.
When creating the directory and creating the inode of iag in diReadSpecial(),
read the page of fixed disk inode (AIT) in raw mode in read_metapage(), the
metapage data it returns is corrupted, which causes the nlink value of 0 to be
assigned to the iag inode when executing copy_from_dinode(), which ultimately
causes a deadlock when entering diFree().
To avoid this, first check the nlink value of dinode before setting iag inode.
[1]
WARNING: possible recursive locking detected
6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0 Not tainted
--------------------------------------------
syz-executor301/5309 is trying to acquire lock:
ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diFree+0x37c/0x2fb0 fs/jfs/jfs_imap.c:889
but task is already holding lock:
ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diAlloc+0x1b6/0x1630
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(imap->im_aglock[index]));
lock(&(imap->im_aglock[index]));
*** DEADLOCK ***
May be due to missing lock nesting notation
5 locks held by syz-executor301/5309:
#0: ffff8880422a4420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515
#1: ffff88804755b390 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline]
#1: ffff88804755b390 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: filename_create+0x260/0x540 fs/namei.c:4026
#2: ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diAlloc+0x1b6/0x1630
#3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diNewIAG fs/jfs/jfs_imap.c:2460 [inline]
#3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
#3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diAllocAG+0x4b7/0x1e50 fs/jfs/jfs_imap.c:1669
#4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diNewIAG fs/jfs/jfs_imap.c:2477 [inline]
#4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
#4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diAllocAG+0x869/0x1e50 fs/jfs/jfs_imap.c:1669
stack backtrace:
CPU: 0 UID: 0 PID: 5309 Comm: syz-executor301 Not tainted 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037
check_deadlock kernel/locking/lockdep.c:3089 [inline]
validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891
__lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
diFree+0x37c/0x2fb0 fs/jfs/jfs_imap.c:889
jfs_evict_inode+0x32d/0x440 fs/jfs/inode.c:156
evict+0x4e8/0x9b0 fs/inode.c:725
diFreeSpecial fs/jfs/jfs_imap.c:552 [inline]
duplicateIXtree+0x3c6/0x550 fs/jfs/jfs_imap.c:3022
diNewIAG fs/jfs/jfs_imap.c:2597 [inline]
diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
diAllocAG+0x17dc/0x1e50 fs/jfs/jfs_imap.c:1669
diAlloc+0x1d2/0x1630 fs/jfs/jfs_imap.c:1590
ialloc+0x8f/0x900 fs/jfs/jfs_inode.c:56
jfs_mkdir+0x1c5/0xba0 fs/jfs/namei.c:225
vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257
do_mkdirat+0x264/0x3a0 fs/namei.c:4280
__do_sys_mkdirat fs/namei.c:4295 [inline]
__se_sys_mkdirat fs/namei.c:4293 [inline]
__x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293
do_syscall_x64 arch/x86/en
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
jfs: Fix uninit-value access of imap allocated in the diMount() function
syzbot reports that hex_dump_to_buffer is using uninit-value:
=====================================================
BUG: KMSAN: uninit-value in hex_dump_to_buffer+0x888/0x1100 lib/hexdump.c:171
hex_dump_to_buffer+0x888/0x1100 lib/hexdump.c:171
print_hex_dump+0x13d/0x3e0 lib/hexdump.c:276
diFree+0x5ba/0x4350 fs/jfs/jfs_imap.c:876
jfs_evict_inode+0x510/0x550 fs/jfs/inode.c:156
evict+0x723/0xd10 fs/inode.c:796
iput_final fs/inode.c:1946 [inline]
iput+0x97b/0xdb0 fs/inode.c:1972
txUpdateMap+0xf3e/0x1150 fs/jfs/jfs_txnmgr.c:2367
txLazyCommit fs/jfs/jfs_txnmgr.c:2664 [inline]
jfs_lazycommit+0x627/0x11d0 fs/jfs/jfs_txnmgr.c:2733
kthread+0x6b9/0xef0 kernel/kthread.c:464
ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Uninit was created at:
slab_post_alloc_hook mm/slub.c:4121 [inline]
slab_alloc_node mm/slub.c:4164 [inline]
__kmalloc_cache_noprof+0x8e3/0xdf0 mm/slub.c:4320
kmalloc_noprof include/linux/slab.h:901 [inline]
diMount+0x61/0x7f0 fs/jfs/jfs_imap.c:105
jfs_mount+0xa8e/0x11d0 fs/jfs/jfs_mount.c:176
jfs_fill_super+0xa47/0x17c0 fs/jfs/super.c:523
get_tree_bdev_flags+0x6ec/0x910 fs/super.c:1636
get_tree_bdev+0x37/0x50 fs/super.c:1659
jfs_get_tree+0x34/0x40 fs/jfs/super.c:635
vfs_get_tree+0xb1/0x5a0 fs/super.c:1814
do_new_mount+0x71f/0x15e0 fs/namespace.c:3560
path_mount+0x742/0x1f10 fs/namespace.c:3887
do_mount fs/namespace.c:3900 [inline]
__do_sys_mount fs/namespace.c:4111 [inline]
__se_sys_mount+0x71f/0x800 fs/namespace.c:4088
__x64_sys_mount+0xe4/0x150 fs/namespace.c:4088
x64_sys_call+0x39bf/0x3c30 arch/x86/include/generated/asm/syscalls_64.h:166
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
=====================================================
The reason is that imap is not properly initialized after memory
allocation. It will cause the snprintf() function to write uninitialized
data into linebuf within hex_dump_to_buffer().
Fix this by using kzalloc instead of kmalloc to clear its content at the
beginning in diMount().
In the Linux kernel, the following vulnerability has been resolved:
bus: mhi: host: Fix race between unprepare and queue_buf
A client driver may use mhi_unprepare_from_transfer() to quiesce
incoming data during the client driver's tear down. The client driver
might also be processing data at the same time, resulting in a call to
mhi_queue_buf() which will invoke mhi_gen_tre(). If mhi_gen_tre() runs
after mhi_unprepare_from_transfer() has torn down the channel, a panic
will occur due to an invalid dereference leading to a page fault.
This occurs because mhi_gen_tre() does not verify the channel state
after locking it. Fix this by having mhi_gen_tre() confirm the channel
state is valid, or return error to avoid accessing deinitialized data.
[mani: added stable tag]
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: Fix accessing freed irq affinity_hint
In stmmac_request_irq_multi_msi(), a pointer to the stack variable
cpu_mask is passed to irq_set_affinity_hint(). This value is stored in
irq_desc->affinity_hint, but once stmmac_request_irq_multi_msi()
returns, the pointer becomes dangling.
The affinity_hint is exposed via procfs with S_IRUGO permissions,
allowing any unprivileged process to read it. Accessing this stale
pointer can lead to:
- a kernel oops or panic if the referenced memory has been released and
unmapped, or
- leakage of kernel data into userspace if the memory is re-used for
other purposes.
All platforms that use stmmac with PCI MSI (Intel, Loongson, etc) are
affected.
In the Linux kernel, the following vulnerability has been resolved:
media: venus: hfi_parser: refactor hfi packet parsing logic
words_count denotes the number of words in total payload, while data
points to payload of various property within it. When words_count
reaches last word, data can access memory beyond the total payload. This
can lead to OOB access. With this patch, the utility api for handling
individual properties now returns the size of data consumed. Accordingly
remaining bytes are calculated before parsing the payload, thereby
eliminates the OOB access possibilities.
In the Linux kernel, the following vulnerability has been resolved:
media: venus: hfi_parser: add check to avoid out of bound access
There is a possibility that init_codecs is invoked multiple times during
manipulated payload from video firmware. In such case, if codecs_count
can get incremented to value more than MAX_CODEC_NUM, there can be OOB
access. Reset the count so that it always starts from beginning.
In the Linux kernel, the following vulnerability has been resolved:
media: venus: hfi: add check to handle incorrect queue size
qsize represents size of shared queued between driver and video
firmware. Firmware can modify this value to an invalid large value. In
such situation, empty_space will be bigger than the space actually
available. Since new_wr_idx is not checked, so the following code will
result in an OOB write.
...
qsize = qhdr->q_size
if (wr_idx >= rd_idx)
empty_space = qsize - (wr_idx - rd_idx)
....
if (new_wr_idx < qsize) {
memcpy(wr_ptr, packet, dwords << 2) --> OOB write
Add check to ensure qsize is within the allocated size while
reading and writing packets into the queue.
In the Linux kernel, the following vulnerability has been resolved:
media: venus: hfi: add a check to handle OOB in sfr region
sfr->buf_size is in shared memory and can be modified by malicious user.
OOB write is possible when the size is made higher than actual sfr data
buffer. Cap the size to allocated size for such cases.
In the Linux kernel, the following vulnerability has been resolved:
media: mediatek: vcodec: Fix a resource leak related to the scp device in FW initialization
On Mediatek devices with a system companion processor (SCP) the mtk_scp
structure has to be removed explicitly to avoid a resource leak.
Free the structure in case the allocation of the firmware structure fails
during the firmware initialization.
In the Linux kernel, the following vulnerability has been resolved:
sctp: detect and prevent references to a freed transport in sendmsg
sctp_sendmsg() re-uses associations and transports when possible by
doing a lookup based on the socket endpoint and the message destination
address, and then sctp_sendmsg_to_asoc() sets the selected transport in
all the message chunks to be sent.
There's a possible race condition if another thread triggers the removal
of that selected transport, for instance, by explicitly unbinding an
address with setsockopt(SCTP_SOCKOPT_BINDX_REM), after the chunks have
been set up and before the message is sent. This can happen if the send
buffer is full, during the period when the sender thread temporarily
releases the socket lock in sctp_wait_for_sndbuf().
This causes the access to the transport data in
sctp_outq_select_transport(), when the association outqueue is flushed,
to result in a use-after-free read.
This change avoids this scenario by having sctp_transport_free() signal
the freeing of the transport, tagging it as "dead". In order to do this,
the patch restores the "dead" bit in struct sctp_transport, which was
removed in
commit 47faa1e4c50e ("sctp: remove the dead field of sctp_transport").
Then, in the scenario where the sender thread has released the socket
lock in sctp_wait_for_sndbuf(), the bit is checked again after
re-acquiring the socket lock to detect the deletion. This is done while
holding a reference to the transport to prevent it from being freed in
the process.
If the transport was deleted while the socket lock was relinquished,
sctp_sendmsg_to_asoc() will return -EAGAIN to let userspace retry the
send.
The bug was found by a private syzbot instance (see the error report [1]
and the C reproducer that triggers it [2]).