The patch titled
Subject: fs/minix: don't allow getting deleted inodes
has been added to the -mm tree. Its filename is
fs-minix-dont-allow-getting-deleted-inodes.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/fs-minix-dont-allow-getting-deleted-inodes.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/fs-minix-dont-allow-getting-deleted-inodes.patch
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------------------------------------------------------
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Subject: fs/minix: don't allow getting deleted inodes
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.
Link: http://lkml.kernel.org/r/20200628060846.682158-3-ebiggers@xxxxxxxxxx
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+a9ac3de1b5de5fb10efc@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot+df958cf5688a96ad3287@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Qiujun Huang <anenbupt@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/minix/inode.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
--- a/fs/minix/inode.c~fs-minix-dont-allow-getting-deleted-inodes
+++ a/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);
_
Patches currently in -mm which might be from ebiggers@xxxxxxxxxx are
fs-minix-check-return-value-of-sb_getblk.patch
fs-minix-dont-allow-getting-deleted-inodes.patch
fs-minix-reject-too-large-maximum-file-size.patch
fs-minix-set-s_maxbytes-correctly.patch
fs-minix-fix-block-limit-check-for-v1-filesystems.patch
fs-minix-remove-expected-error-message-in-block_to_path.patch
