2020-01-14 05:45:08

by quanyang wang

Subject: [PATCH] ubifs: fix memory leak from c->sup_node

From: Quanyang Wang <[email protected]>

The c->sup_node is allocated in function ubifs_read_sb_node but
is not freed. This will cause memory leak as below:

unreferenced object 0xbc9ce000 (size 4096):
comm "mount", pid 500, jiffies 4294952946 (age 315.820s)
hex dump (first 32 bytes):
31 18 10 06 06 7b f1 11 02 00 00 00 00 00 00 00 1....{..........
00 10 00 00 06 00 00 00 00 00 00 00 08 00 00 00 ................
backtrace:
[<d1c503cd>] ubifs_read_superblock+0x48/0xebc
[<a20e14bd>] ubifs_mount+0x974/0x1420
[<8589ecc3>] legacy_get_tree+0x2c/0x50
[<5f1fb889>] vfs_get_tree+0x28/0xfc
[<bbfc7939>] do_mount+0x4f8/0x748
[<4151f538>] ksys_mount+0x78/0xa0
[<d59910a9>] ret_fast_syscall+0x0/0x54
[<1cc40005>] 0x7ea02790

Free it in ubifs_umount and in the error path of mount_ubifs.

Fixes: fd6150051bec ("ubifs: Store read superblock node")
Signed-off-by: Quanyang Wang <[email protected]>
---
fs/ubifs/super.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 7d4547e5202d..a4412c259bb3 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1599,6 +1599,7 @@ static int mount_ubifs(struct ubifs_info *c)
vfree(c->ileb_buf);
vfree(c->sbuf);
kfree(c->bottom_up_buf);
+ kfree(c->sup_node);
ubifs_debugging_exit(c);
return err;
}
@@ -1641,6 +1642,7 @@ static void ubifs_umount(struct ubifs_info *c)
vfree(c->ileb_buf);
vfree(c->sbuf);
kfree(c->bottom_up_buf);
+ kfree(c->sup_node);
ubifs_debugging_exit(c);
}

--
2.17.1

2020-01-14 09:23:11

by Sascha Hauer

Subject: Re: [PATCH] ubifs: fix memory leak from c->sup_node

On Tue, Jan 14, 2020 at 01:43:11PM +0800, [email protected] wrote:
> From: Quanyang Wang <[email protected]>
>
> The c->sup_node is allocated in function ubifs_read_sb_node but
> is not freed. This will cause memory leak as below:
>
> unreferenced object 0xbc9ce000 (size 4096):
> comm "mount", pid 500, jiffies 4294952946 (age 315.820s)
> hex dump (first 32 bytes):
> 31 18 10 06 06 7b f1 11 02 00 00 00 00 00 00 00 1....{..........
> 00 10 00 00 06 00 00 00 00 00 00 00 08 00 00 00 ................
> backtrace:
> [<d1c503cd>] ubifs_read_superblock+0x48/0xebc
> [<a20e14bd>] ubifs_mount+0x974/0x1420
> [<8589ecc3>] legacy_get_tree+0x2c/0x50
> [<5f1fb889>] vfs_get_tree+0x28/0xfc
> [<bbfc7939>] do_mount+0x4f8/0x748
> [<4151f538>] ksys_mount+0x78/0xa0
> [<d59910a9>] ret_fast_syscall+0x0/0x54
> [<1cc40005>] 0x7ea02790
>
> Free it in ubifs_umount and in the error path of mount_ubifs.
>
> Fixes: fd6150051bec ("ubifs: Store read superblock node")
> Signed-off-by: Quanyang Wang <[email protected]>

Looks good.

Reviewed-by: Sascha Hauer <[email protected]>

Sascha

> ---
> fs/ubifs/super.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
> index 7d4547e5202d..a4412c259bb3 100644
> --- a/fs/ubifs/super.c
> +++ b/fs/ubifs/super.c
> @@ -1599,6 +1599,7 @@ static int mount_ubifs(struct ubifs_info *c)
> vfree(c->ileb_buf);
> vfree(c->sbuf);
> kfree(c->bottom_up_buf);
> + kfree(c->sup_node);
> ubifs_debugging_exit(c);
> return err;
> }
> @@ -1641,6 +1642,7 @@ static void ubifs_umount(struct ubifs_info *c)
> vfree(c->ileb_buf);
> vfree(c->sbuf);
> kfree(c->bottom_up_buf);
> + kfree(c->sup_node);
> ubifs_debugging_exit(c);
> }
>
> --
> 2.17.1
>
>

--
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2020-01-17 04:46:31

by Richard Weinberger

Subject: Re: [PATCH] ubifs: fix memory leak from c->sup_node

On Tue, Jan 14, 2020 at 10:21 AM Sascha Hauer <[email protected]> wrote:
>
> On Tue, Jan 14, 2020 at 01:43:11PM +0800, [email protected] wrote:
> > From: Quanyang Wang <[email protected]>
> >
> > The c->sup_node is allocated in function ubifs_read_sb_node but
> > is not freed. This will cause memory leak as below:
> >
> > unreferenced object 0xbc9ce000 (size 4096):
> > comm "mount", pid 500, jiffies 4294952946 (age 315.820s)
> > hex dump (first 32 bytes):
> > 31 18 10 06 06 7b f1 11 02 00 00 00 00 00 00 00 1....{..........
> > 00 10 00 00 06 00 00 00 00 00 00 00 08 00 00 00 ................
> > backtrace:
> > [<d1c503cd>] ubifs_read_superblock+0x48/0xebc
> > [<a20e14bd>] ubifs_mount+0x974/0x1420
> > [<8589ecc3>] legacy_get_tree+0x2c/0x50
> > [<5f1fb889>] vfs_get_tree+0x28/0xfc
> > [<bbfc7939>] do_mount+0x4f8/0x748
> > [<4151f538>] ksys_mount+0x78/0xa0
> > [<d59910a9>] ret_fast_syscall+0x0/0x54
> > [<1cc40005>] 0x7ea02790
> >
> > Free it in ubifs_umount and in the error path of mount_ubifs.
> >
> > Fixes: fd6150051bec ("ubifs: Store read superblock node")
> > Signed-off-by: Quanyang Wang <[email protected]>
>
> Looks good.
>
> Reviewed-by: Sascha Hauer <[email protected]>

Hm, this one is not in patchwork.
Anyway, applied. Thanks for fixing!

--
Thanks,
//richard