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| author | Ryusuke Konishi <konishi.ryusuke@gmail.com> | 2022-10-07 10:52:26 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-10-12 04:05:45 +0200 |
| commit | d0d51a97063db4704a5ef6bc978dddab1636a306 (patch) | |
| tree | f1d4ec9dd7a1781bbef5bae300e4353088689ce5 /fs | |
| parent | nilfs2: fix NULL pointer dereference at nilfs_bmap_lookup_at_level() (diff) | |
| download | linux-d0d51a97063db4704a5ef6bc978dddab1636a306.tar.xz linux-d0d51a97063db4704a5ef6bc978dddab1636a306.zip | |
nilfs2: fix leak of nilfs_root in case of writer thread creation failure
If nilfs_attach_log_writer() failed to create a log writer thread, it
frees a data structure of the log writer without any cleanup. After
commit e912a5b66837 ("nilfs2: use root object to get ifile"), this causes
a leak of struct nilfs_root, which started to leak an ifile metadata inode
and a kobject on that struct.
In addition, if the kernel is booted with panic_on_warn, the above
ifile metadata inode leak will cause the following panic when the
nilfs2 kernel module is removed:
kmem_cache_destroy nilfs2_inode_cache: Slab cache still has objects when
called from nilfs_destroy_cachep+0x16/0x3a [nilfs2]
WARNING: CPU: 8 PID: 1464 at mm/slab_common.c:494 kmem_cache_destroy+0x138/0x140
...
RIP: 0010:kmem_cache_destroy+0x138/0x140
Code: 00 20 00 00 e8 a9 55 d8 ff e9 76 ff ff ff 48 8b 53 60 48 c7 c6 20 70 65 86 48 c7 c7 d8 69 9c 86 48 8b 4c 24 28 e8 ef 71 c7 00 <0f> 0b e9 53 ff ff ff c3 48 81 ff ff 0f 00 00 77 03 31 c0 c3 53 48
...
Call Trace:
<TASK>
? nilfs_palloc_freev.cold.24+0x58/0x58 [nilfs2]
nilfs_destroy_cachep+0x16/0x3a [nilfs2]
exit_nilfs_fs+0xa/0x1b [nilfs2]
__x64_sys_delete_module+0x1d9/0x3a0
? __sanitizer_cov_trace_pc+0x1a/0x50
? syscall_trace_enter.isra.19+0x119/0x190
do_syscall_64+0x34/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
...
</TASK>
Kernel panic - not syncing: panic_on_warn set ...
This patch fixes these issues by calling nilfs_detach_log_writer() cleanup
function if spawning the log writer thread fails.
Link: https://lkml.kernel.org/r/20221007085226.57667-1-konishi.ryusuke@gmail.com
Fixes: e912a5b66837 ("nilfs2: use root object to get ifile")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+7381dc4ad60658ca4c05@syzkaller.appspotmail.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/nilfs2/segment.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index 0afe0832c754..5276ab525f01 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -2786,10 +2786,9 @@ int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root) inode_attach_wb(nilfs->ns_bdev->bd_inode, NULL); err = nilfs_segctor_start_thread(nilfs->ns_writer); - if (err) { - kfree(nilfs->ns_writer); - nilfs->ns_writer = NULL; - } + if (unlikely(err)) + nilfs_detach_log_writer(sb); + return err; } |