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* memory leak in kobject_set_name_vargs (3)
@ 2020-09-21 10:02 syzbot
  2020-09-22 16:24 ` [PATCH] ext4: fix leaking sysfs kobject after failed mount Eric Biggers
  0 siblings, 1 reply; 4+ messages in thread
From: syzbot @ 2020-09-21 10:02 UTC (permalink / raw)
  To: adilger.kernel, linux-ext4, linux-kernel, syzkaller-bugs, tytso

Hello,

syzbot found the following issue on:

HEAD commit:    bdcf11de Merge tag 'riscv-for-linus-5.9-rc6' of git://git...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=179e18d3900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a1f3c5052e8097e9
dashboard link: https://syzkaller.appspot.com/bug?extid=9f864abad79fae7c17e1
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14c33cad900000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=154bc6c3900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9f864abad79fae7c17e1@syzkaller.appspotmail.com

BUG: memory leak
unreferenced object 0xffff88811a0d75c0 (size 32):
  comm "syz-executor307", pid 6444, jiffies 4294941412 (age 12.730s)
  hex dump (first 32 bytes):
    6c 6f 6f 70 30 00 00 00 00 00 00 00 00 00 00 00  loop0...........
    01 00 00 00 03 00 00 00 2b 00 00 00 00 00 00 00  ........+.......
  backtrace:
    [<00000000f89b0bef>] kstrdup+0x36/0x70 mm/util.c:60
    [<000000004b68a0da>] kstrdup_const+0x35/0x60 mm/util.c:82
    [<000000008eb65a51>] kvasprintf_const+0x72/0xe0 lib/kasprintf.c:48
    [<00000000691729e7>] kobject_set_name_vargs+0x3b/0xe0 lib/kobject.c:289
    [<00000000dfb16dfe>] kobject_add_varg lib/kobject.c:384 [inline]
    [<00000000dfb16dfe>] kobject_init_and_add+0x6d/0xc0 lib/kobject.c:473
    [<000000005849f02f>] ext4_register_sysfs+0x6b/0x160 fs/ext4/sysfs.c:508
    [<0000000027523718>] ext4_fill_super+0x2d04/0x46c0 fs/ext4/super.c:4799
    [<0000000095f0e4f3>] mount_bdev+0x1d3/0x210 fs/super.c:1417
    [<00000000415e8d00>] legacy_get_tree+0x26/0x70 fs/fs_context.c:592
    [<00000000bf686d81>] vfs_get_tree+0x28/0xe0 fs/super.c:1547
    [<00000000fd6d6aba>] do_new_mount fs/namespace.c:2875 [inline]
    [<00000000fd6d6aba>] path_mount+0x90e/0xda0 fs/namespace.c:3192
    [<000000008d02c1d0>] do_mount fs/namespace.c:3205 [inline]
    [<000000008d02c1d0>] __do_sys_mount fs/namespace.c:3413 [inline]
    [<000000008d02c1d0>] __se_sys_mount fs/namespace.c:3390 [inline]
    [<000000008d02c1d0>] __x64_sys_mount+0x140/0x190 fs/namespace.c:3390
    [<000000001c682859>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    [<0000000095c447b2>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88811a0d74e0 (size 32):
  comm "syz-executor307", pid 6451, jiffies 4294941943 (age 7.420s)
  hex dump (first 32 bytes):
    6c 6f 6f 70 30 00 00 00 00 00 00 00 00 00 00 00  loop0...........
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000f89b0bef>] kstrdup+0x36/0x70 mm/util.c:60
    [<000000004b68a0da>] kstrdup_const+0x35/0x60 mm/util.c:82
    [<000000008eb65a51>] kvasprintf_const+0x72/0xe0 lib/kasprintf.c:48
    [<00000000691729e7>] kobject_set_name_vargs+0x3b/0xe0 lib/kobject.c:289
    [<00000000dfb16dfe>] kobject_add_varg lib/kobject.c:384 [inline]
    [<00000000dfb16dfe>] kobject_init_and_add+0x6d/0xc0 lib/kobject.c:473
    [<000000005849f02f>] ext4_register_sysfs+0x6b/0x160 fs/ext4/sysfs.c:508
    [<0000000027523718>] ext4_fill_super+0x2d04/0x46c0 fs/ext4/super.c:4799
    [<0000000095f0e4f3>] mount_bdev+0x1d3/0x210 fs/super.c:1417
    [<00000000415e8d00>] legacy_get_tree+0x26/0x70 fs/fs_context.c:592
    [<00000000bf686d81>] vfs_get_tree+0x28/0xe0 fs/super.c:1547
    [<00000000fd6d6aba>] do_new_mount fs/namespace.c:2875 [inline]
    [<00000000fd6d6aba>] path_mount+0x90e/0xda0 fs/namespace.c:3192
    [<000000008d02c1d0>] do_mount fs/namespace.c:3205 [inline]
    [<000000008d02c1d0>] __do_sys_mount fs/namespace.c:3413 [inline]
    [<000000008d02c1d0>] __se_sys_mount fs/namespace.c:3390 [inline]
    [<000000008d02c1d0>] __x64_sys_mount+0x140/0x190 fs/namespace.c:3390
    [<000000001c682859>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    [<0000000095c447b2>] entry_SYSCALL_64_after_hwframe+0x44/0xa9



---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

^ permalink raw reply	[flat|nested] 4+ messages in thread
* [PATCH] ext4: fix leaking sysfs kobject after failed mount
  2020-09-21 10:02 memory leak in kobject_set_name_vargs (3) syzbot
@ 2020-09-22 16:24 ` Eric Biggers
  2020-09-24  9:08   ` Jan Kara
  0 siblings, 1 reply; 4+ messages in thread
From: Eric Biggers @ 2020-09-22 16:24 UTC (permalink / raw)
  To: linux-ext4, Theodore Ts'o
  Cc: syzkaller-bugs, linux-kernel, stable, syzbot+9f864abad79fae7c17e1

From: Eric Biggers <ebiggers@google.com>

ext4_unregister_sysfs() only deletes the kobject.  The reference to it
needs to be put separately, like ext4_put_super() does.

This addresses the syzbot report
"memory leak in kobject_set_name_vargs (3)"
(https://syzkaller.appspot.com/bug?extid=9f864abad79fae7c17e1).

Reported-by: syzbot+9f864abad79fae7c17e1@syzkaller.appspotmail.com
Fixes: 72ba74508b28 ("ext4: release sysfs kobject when failing to enable quotas on mount")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 fs/ext4/super.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ea425b49b345..41953b86ffe3 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4872,6 +4872,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 
 failed_mount8:
 	ext4_unregister_sysfs(sb);
+	kobject_put(&sbi->s_kobj);
 failed_mount7:
 	ext4_unregister_li_request(sb);
 failed_mount6:

base-commit: ba4f184e126b751d1bffad5897f263108befc780
-- 
2.28.0


^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH] ext4: fix leaking sysfs kobject after failed mount
  2020-09-22 16:24 ` [PATCH] ext4: fix leaking sysfs kobject after failed mount Eric Biggers
@ 2020-09-24  9:08   ` Jan Kara
  2020-10-03  4:56     ` Theodore Y. Ts'o
  0 siblings, 1 reply; 4+ messages in thread
From: Jan Kara @ 2020-09-24  9:08 UTC (permalink / raw)
  To: Eric Biggers
  Cc: linux-ext4, Theodore Ts'o, syzkaller-bugs, linux-kernel,
	stable, syzbot+9f864abad79fae7c17e1

On Tue 22-09-20 09:24:56, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> ext4_unregister_sysfs() only deletes the kobject.  The reference to it
> needs to be put separately, like ext4_put_super() does.
> 
> This addresses the syzbot report
> "memory leak in kobject_set_name_vargs (3)"
> (https://syzkaller.appspot.com/bug?extid=9f864abad79fae7c17e1).
> 
> Reported-by: syzbot+9f864abad79fae7c17e1@syzkaller.appspotmail.com
> Fixes: 72ba74508b28 ("ext4: release sysfs kobject when failing to enable quotas on mount")
> Cc: stable@vger.kernel.org
> Signed-off-by: Eric Biggers <ebiggers@google.com>

Looks good. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/ext4/super.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index ea425b49b345..41953b86ffe3 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -4872,6 +4872,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
>  
>  failed_mount8:
>  	ext4_unregister_sysfs(sb);
> +	kobject_put(&sbi->s_kobj);
>  failed_mount7:
>  	ext4_unregister_li_request(sb);
>  failed_mount6:
> 
> base-commit: ba4f184e126b751d1bffad5897f263108befc780
> -- 
> 2.28.0
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

^ permalink raw reply	[flat|nested] 4+ messages in thread
* Re: [PATCH] ext4: fix leaking sysfs kobject after failed mount
  2020-09-24  9:08   ` Jan Kara
@ 2020-10-03  4:56     ` Theodore Y. Ts'o
  0 siblings, 0 replies; 4+ messages in thread
From: Theodore Y. Ts'o @ 2020-10-03  4:56 UTC (permalink / raw)
  To: Jan Kara
  Cc: Eric Biggers, linux-ext4, syzkaller-bugs, linux-kernel, stable,
	syzbot+9f864abad79fae7c17e1

On Thu, Sep 24, 2020 at 11:08:59AM +0200, Jan Kara wrote:
> On Tue 22-09-20 09:24:56, Eric Biggers wrote:
> > From: Eric Biggers <ebiggers@google.com>
> > 
> > ext4_unregister_sysfs() only deletes the kobject.  The reference to it
> > needs to be put separately, like ext4_put_super() does.
> > 
> > This addresses the syzbot report
> > "memory leak in kobject_set_name_vargs (3)"
> > (https://syzkaller.appspot.com/bug?extid=9f864abad79fae7c17e1).
> > 
> > Reported-by: syzbot+9f864abad79fae7c17e1@syzkaller.appspotmail.com
> > Fixes: 72ba74508b28 ("ext4: release sysfs kobject when failing to enable quotas on mount")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Eric Biggers <ebiggers@google.com>
> 
> Looks good. You can add:
> 
> Reviewed-by: Jan Kara <jack@suse.cz>

Thanks, applied.

					- Ted

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-10-03  4:56 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-09-21 10:02 memory leak in kobject_set_name_vargs (3) syzbot
2020-09-22 16:24 ` [PATCH] ext4: fix leaking sysfs kobject after failed mount Eric Biggers
2020-09-24  9:08   ` Jan Kara
2020-10-03  4:56     ` Theodore Y. Ts'o

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