In the Linux kernel, the following vulnerability has been resolved:
jfs: fix null ptr deref in dtInsertEntry
[syzbot reported]
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 5061 Comm: syz-executor404 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:dtInsertEntry+0xd0c/0x1780 fs/jfs/jfs_dtree.c:3713
...
[Analyze]
In dtInsertEntry(), when the pointer h has the same value as p, after writing
name in UniStrncpy_to_le(), p->header.flag will be cleared. This will cause the
previously true judgment "p->header.flag & BT-LEAF" to change to no after writing
the name operation, this leads to entering an incorrect branch and accessing the
uninitialized object ih when judging this condition for the second time.
[Fix]
After got the page, check freelist first, if freelist == 0 then exit dtInsert()
and return -EINVAL.
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to cover read extent cache access with lock
syzbot reports a f2fs bug as below:
BUG: KASAN: slab-use-after-free in sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
Read of size 4 at addr ffff8880739ab220 by task syz-executor200/5097
CPU: 0 PID: 5097 Comm: syz-executor200 Not tainted 6.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
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
sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
do_read_inode fs/f2fs/inode.c:509 [inline]
f2fs_iget+0x33e1/0x46e0 fs/f2fs/inode.c:560
f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237
generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413
exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444
exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584
do_handle_to_path fs/fhandle.c:155 [inline]
handle_to_path fs/fhandle.c:210 [inline]
do_handle_open+0x495/0x650 fs/fhandle.c:226
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
We missed to cover sanity_check_extent_cache() w/ extent cache lock,
so, below race case may happen, result in use after free issue.
- f2fs_iget
- do_read_inode
- f2fs_init_read_extent_tree
: add largest extent entry in to cache
- shrink
- f2fs_shrink_read_extent_tree
- __shrink_extent_tree
- __detach_extent_node
: drop largest extent entry
- sanity_check_extent_cache
: access et->largest w/o lock
let's refactor sanity_check_extent_cache() to avoid extent cache access
and call it before f2fs_init_read_extent_tree() to fix this issue.
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to do sanity check on F2FS_INLINE_DATA flag in inode during GC
syzbot reports a f2fs bug as below:
------------[ cut here ]------------
kernel BUG at fs/f2fs/inline.c:258!
CPU: 1 PID: 34 Comm: kworker/u8:2 Not tainted 6.9.0-rc6-syzkaller-00012-g9e4bc4bcae01 #0
RIP: 0010:f2fs_write_inline_data+0x781/0x790 fs/f2fs/inline.c:258
Call Trace:
f2fs_write_single_data_page+0xb65/0x1d60 fs/f2fs/data.c:2834
f2fs_write_cache_pages fs/f2fs/data.c:3133 [inline]
__f2fs_write_data_pages fs/f2fs/data.c:3288 [inline]
f2fs_write_data_pages+0x1efe/0x3a90 fs/f2fs/data.c:3315
do_writepages+0x35b/0x870 mm/page-writeback.c:2612
__writeback_single_inode+0x165/0x10b0 fs/fs-writeback.c:1650
writeback_sb_inodes+0x905/0x1260 fs/fs-writeback.c:1941
wb_writeback+0x457/0xce0 fs/fs-writeback.c:2117
wb_do_writeback fs/fs-writeback.c:2264 [inline]
wb_workfn+0x410/0x1090 fs/fs-writeback.c:2304
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa12/0x17c0 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f2/0x390 kernel/kthread.c:388
ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
The root cause is: inline_data inode can be fuzzed, so that there may
be valid blkaddr in its direct node, once f2fs triggers background GC
to migrate the block, it will hit f2fs_bug_on() during dirty page
writeback.
Let's add sanity check on F2FS_INLINE_DATA flag in inode during GC,
so that, it can forbid migrating inline_data inode's data block for
fixing.
In the Linux kernel, the following vulnerability has been resolved:
jfs: Fix shift-out-of-bounds in dbDiscardAG
When searching for the next smaller log2 block, BLKSTOL2() returned 0,
causing shift exponent -1 to be negative.
This patch fixes the issue by exiting the loop directly when negative
shift is found.
In the Linux kernel, the following vulnerability has been resolved:
nvme: apple: fix device reference counting
Drivers must call nvme_uninit_ctrl after a successful nvme_init_ctrl.
Split the allocation side out to make the error handling boundary easier
to navigate. The apple driver had been doing this wrong, leaking the
controller device memory on a tagset failure.
In the Linux kernel, the following vulnerability has been resolved:
gpio: prevent potential speculation leaks in gpio_device_get_desc()
Userspace may trigger a speculative read of an address outside the gpio
descriptor array.
Users can do that by calling gpio_ioctl() with an offset out of range.
Offset is copied from user and then used as an array index to get
the gpio descriptor without sanitization in gpio_device_get_desc().
This change ensures that the offset is sanitized by using
array_index_nospec() to mitigate any possibility of speculative
information leaks.
This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.
In the Linux kernel, the following vulnerability has been resolved:
memcg: protect concurrent access to mem_cgroup_idr
Commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure after
many small jobs") decoupled the memcg IDs from the CSS ID space to fix the
cgroup creation failures. It introduced IDR to maintain the memcg ID
space. The IDR depends on external synchronization mechanisms for
modifications. For the mem_cgroup_idr, the idr_alloc() and idr_replace()
happen within css callback and thus are protected through cgroup_mutex
from concurrent modifications. However idr_remove() for mem_cgroup_idr
was not protected against concurrency and can be run concurrently for
different memcgs when they hit their refcnt to zero. Fix that.
We have been seeing list_lru based kernel crashes at a low frequency in
our fleet for a long time. These crashes were in different part of
list_lru code including list_lru_add(), list_lru_del() and reparenting
code. Upon further inspection, it looked like for a given object (dentry
and inode), the super_block's list_lru didn't have list_lru_one for the
memcg of that object. The initial suspicions were either the object is
not allocated through kmem_cache_alloc_lru() or somehow
memcg_list_lru_alloc() failed to allocate list_lru_one() for a memcg but
returned success. No evidence were found for these cases.
Looking more deeply, we started seeing situations where valid memcg's id
is not present in mem_cgroup_idr and in some cases multiple valid memcgs
have same id and mem_cgroup_idr is pointing to one of them. So, the most
reasonable explanation is that these situations can happen due to race
between multiple idr_remove() calls or race between
idr_alloc()/idr_replace() and idr_remove(). These races are causing
multiple memcgs to acquire the same ID and then offlining of one of them
would cleanup list_lrus on the system for all of them. Later access from
other memcgs to the list_lru cause crashes due to missing list_lru_one.