| Message ID | 20191024082535.1022-1-richard@nod.at |
|---|---|
| State | Accepted |
| Headers | show |
| Series | Revert "ubifs: Fix memory leak bug in alloc_ubifs_info() error path" | expand |
On Thu, Oct 24, 2019 at 10:25:35AM +0200, Richard Weinberger wrote: > This reverts commit 9163e0184bd7d5f779934d34581843f699ad2ffd. > > At the point when ubifs_fill_super() runs, we have already a reference > to the super block. So upon deactivate_locked_super() c will get > free()'ed via ->kill_sb(). And without a revert, trying to mount a UBI volume with a squashfs image on it as a UBIFS partition will lead to kernel panics due to the double free. > > Cc: Wenwen Wang <wenwen@cs.uga.edu> > Fixes: 9163e0184bd7 ("ubifs: Fix memory leak bug in alloc_ubifs_info() error path") > Reported-by: https://twitter.com/grsecurity/status/1180609139359277056 > Signed-off-by: Richard Weinberger <richard@nod.at> Tested-by: Romain Izard <romain.izard.pro@gmail.com> > --- > fs/ubifs/super.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c > index 7d4547e5202d..5e1e8ec0589e 100644 > --- a/fs/ubifs/super.c > +++ b/fs/ubifs/super.c > @@ -2267,10 +2267,8 @@ static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags, > } > } else { > err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0); > - if (err) { > - kfree(c); > + if (err) > goto out_deact; > - } > /* We do not support atime */ > sb->s_flags |= SB_ACTIVE; > if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT)) > -- > 2.16.4 >
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index 7d4547e5202d..5e1e8ec0589e 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -2267,10 +2267,8 @@ static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags, } } else { err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0); - if (err) { - kfree(c); + if (err) goto out_deact; - } /* We do not support atime */ sb->s_flags |= SB_ACTIVE; if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
This reverts commit 9163e0184bd7d5f779934d34581843f699ad2ffd. At the point when ubifs_fill_super() runs, we have already a reference to the super block. So upon deactivate_locked_super() c will get free()'ed via ->kill_sb(). Cc: Wenwen Wang <wenwen@cs.uga.edu> Fixes: 9163e0184bd7 ("ubifs: Fix memory leak bug in alloc_ubifs_info() error path") Reported-by: https://twitter.com/grsecurity/status/1180609139359277056 Signed-off-by: Richard Weinberger <richard@nod.at> --- fs/ubifs/super.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)