| From facb03dddec04e4aac1bb2139accdceb04deb1f3 Mon Sep 17 00:00:00 2001 |
| From: Eric Biggers <ebiggers@google.com> |
| Date: Tue, 11 Aug 2020 18:35:27 -0700 |
| Subject: fs/minix: don't allow getting deleted inodes |
| |
| From: Eric Biggers <ebiggers@google.com> |
| |
| commit facb03dddec04e4aac1bb2139accdceb04deb1f3 upstream. |
| |
| If an inode has no links, we need to mark it bad rather than allowing it |
| to be accessed. This avoids WARNINGs in inc_nlink() and drop_nlink() when |
| doing directory operations on a fuzzed filesystem. |
| |
| Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") |
| Reported-by: syzbot+a9ac3de1b5de5fb10efc@syzkaller.appspotmail.com |
| Reported-by: syzbot+df958cf5688a96ad3287@syzkaller.appspotmail.com |
| Signed-off-by: Eric Biggers <ebiggers@google.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Cc: Alexander Viro <viro@zeniv.linux.org.uk> |
| Cc: Qiujun Huang <anenbupt@gmail.com> |
| Cc: <stable@vger.kernel.org> |
| Link: http://lkml.kernel.org/r/20200628060846.682158-3-ebiggers@kernel.org |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/minix/inode.c | 14 ++++++++++++++ |
| 1 file changed, 14 insertions(+) |
| |
| --- a/fs/minix/inode.c |
| +++ b/fs/minix/inode.c |
| @@ -468,6 +468,13 @@ static struct inode *V1_minix_iget(struc |
| iget_failed(inode); |
| return ERR_PTR(-EIO); |
| } |
| + if (raw_inode->i_nlinks == 0) { |
| + printk("MINIX-fs: deleted inode referenced: %lu\n", |
| + inode->i_ino); |
| + brelse(bh); |
| + iget_failed(inode); |
| + return ERR_PTR(-ESTALE); |
| + } |
| inode->i_mode = raw_inode->i_mode; |
| i_uid_write(inode, raw_inode->i_uid); |
| i_gid_write(inode, raw_inode->i_gid); |
| @@ -501,6 +508,13 @@ static struct inode *V2_minix_iget(struc |
| iget_failed(inode); |
| return ERR_PTR(-EIO); |
| } |
| + if (raw_inode->i_nlinks == 0) { |
| + printk("MINIX-fs: deleted inode referenced: %lu\n", |
| + inode->i_ino); |
| + brelse(bh); |
| + iget_failed(inode); |
| + return ERR_PTR(-ESTALE); |
| + } |
| inode->i_mode = raw_inode->i_mode; |
| i_uid_write(inode, raw_inode->i_uid); |
| i_gid_write(inode, raw_inode->i_gid); |