android/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
f1101295c1
android_kernel_xiaomi_sm8450/fs/overlayfs
History
Jiachen Zhang 542d2e799d ovl: drop WARN_ON() dentry is NULL in ovl_encode_fh() 
commit dd524b7f317de8d31d638cbfdc7be4cf9b770e42 upstream.

Some code paths cannot guarantee the inode have any dentry alias. So
WARN_ON() all !dentry may flood the kernel logs.

For example, when an overlayfs inode is watched by inotifywait (1), and
someone is trying to read the /proc/$(pidof inotifywait)/fdinfo/INOTIFY_FD,
at that time if the dentry has been reclaimed by kernel (such as
echo 2 > /proc/sys/vm/drop_caches), there will be a WARN_ON(). The
printed call stack would be like:

    ? show_mark_fhandle+0xf0/0xf0
    show_mark_fhandle+0x4a/0xf0
    ? show_mark_fhandle+0xf0/0xf0
    ? seq_vprintf+0x30/0x50
    ? seq_printf+0x53/0x70
    ? show_mark_fhandle+0xf0/0xf0
    inotify_fdinfo+0x70/0x90
    show_fdinfo.isra.4+0x53/0x70
    seq_show+0x130/0x170
    seq_read+0x153/0x440
    vfs_read+0x94/0x150
    ksys_read+0x5f/0xe0
    do_syscall_64+0x59/0x1e0
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

So let's drop WARN_ON() to avoid kernel log flooding.

Reported-by: Hongbo Yin <yinhongbo@bytedance.com>
Signed-off-by: Jiachen Zhang <zhangjiachen.jaycee@bytedance.com>
Signed-off-by: Tianci Zhang <zhangtianci.1997@bytedance.com>
Fixes: 8ed5eec9d6 ("ovl: encode pure upper file handles")
Cc: <stable@vger.kernel.org> # v4.16
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21 15:15:23 +02:00
..
copy_up.c ovl: fix missing revert_creds() on error path 2021-05-14 09:50:05 +02:00
dir.c ovl: fix warning in ovl_create_real() 2021-12-22 09:30:58 +01:00
export.c ovl: drop WARN_ON() dentry is NULL in ovl_encode_fh() 2022-08-21 15:15:23 +02:00
file.c ovl: fix deadlock in splice write 2021-12-08 09:03:18 +01:00
inode.c ovl: perform vfs_getxattr() with mounter creds 2021-02-17 11:02:22 +01:00
Kconfig docs: fix broken references to text files 2020-04-20 15:35:59 -06:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
namei.c new helper: inode_wrong_type() 2021-09-08 08:49:01 +02:00
overlayfs.h ovl: fix warning in ovl_create_real() 2021-12-22 09:30:58 +01:00
ovl_entry.h ovl: implement volatile-specific fsync error behaviour 2021-02-10 09:29:16 +01:00
readdir.c ovl: invalidate readdir cache on changes to dir with origin 2021-05-14 09:50:35 +02:00
super.c ovl: fix warning in ovl_create_real() 2021-12-22 09:30:58 +01:00
util.c ovl: invalidate readdir cache on changes to dir with origin 2021-05-14 09:50:35 +02:00