Re: memory leak in v2_read_file_info

[Jan Kara]

 Hello,

attached patch should fix this. I'll queue it to my tree.

								Honza

On Tue 22-12-20 02:24:18, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    8653b778 Merge tag 'clk-for-linus' of git://git.kernel.org..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=153fc4db500000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=faf2996955887e91
> dashboard link: https://syzkaller.appspot.com/bug?extid=77779c9b52ab78154b08
> compiler:       gcc (GCC) 10.1.0-syz 20200507
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11c44960d00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13bc8c0b500000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+77779c9b52ab78154b08@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> BUG: memory leak
> unreferenced object 0xffff888110974f00 (size 64):
>   comm "syz-executor849", pid 8516, jiffies 4294942501 (age 13.960s)
>   hex dump (first 32 bytes):
>     00 30 ee 0d 81 88 ff ff 00 00 00 00 00 00 00 00  .0..............
>     00 00 00 00 00 00 00 00 0a 00 00 00 48 00 00 00  ............H...
>   backtrace:
>     [<0000000018aa1939>] kmalloc include/linux/slab.h:552 [inline]
>     [<0000000018aa1939>] v2_read_file_info+0x1ae/0x430 fs/quota/quota_v2.c:122
>     [<000000001061252b>] dquot_load_quota_sb+0x351/0x650 fs/quota/dquot.c:2387
>     [<000000006c1f70f9>] dquot_load_quota_inode fs/quota/dquot.c:2423 [inline]
>     [<000000006c1f70f9>] dquot_load_quota_inode+0xda/0x160 fs/quota/dquot.c:2415
>     [<00000000abace495>] ext4_quota_enable fs/ext4/super.c:6362 [inline]
>     [<00000000abace495>] ext4_enable_quotas+0x1b2/0x2f0 fs/ext4/super.c:6388
>     [<00000000b6d6a975>] ext4_fill_super+0x3bc5/0x5ac0 fs/ext4/super.c:5046
>     [<0000000003a869bd>] mount_bdev+0x223/0x260 fs/super.c:1366
>     [<000000002138e18c>] legacy_get_tree+0x2b/0x90 fs/fs_context.c:592
>     [<0000000096e90d3d>] vfs_get_tree+0x28/0x100 fs/super.c:1496
>     [<00000000eddeeb8e>] do_new_mount fs/namespace.c:2875 [inline]
>     [<00000000eddeeb8e>] path_mount+0xc5e/0x1170 fs/namespace.c:3205
>     [<00000000c52e2f18>] do_mount fs/namespace.c:3218 [inline]
>     [<00000000c52e2f18>] __do_sys_mount fs/namespace.c:3426 [inline]
>     [<00000000c52e2f18>] __se_sys_mount fs/namespace.c:3403 [inline]
>     [<00000000c52e2f18>] __x64_sys_mount+0x18e/0x1d0 fs/namespace.c:3403
>     [<00000000e70a31f4>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<000000007f651b8c>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
> 
> 
> 
> ---
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> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR