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authorEric Biggers <ebiggers@google.com>2020-08-11 18:35:27 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-08-21 11:02:05 +0200
commit5b5c362a4b2e0ed70fcceec5b3cb30665f23295d (patch)
tree3d757e1d1a1f42a27507347296563b31f7f05f2e /fs
parente0aa9371fff5224f5a1330b3f56ec5b63fb240ed (diff)
fs/minix: don't allow getting deleted inodes
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/minix/inode.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index f975d667c539..e4eef5aec0d7 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -472,6 +472,13 @@ static struct inode *V1_minix_iget(struct inode *inode)
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);
@@ -505,6 +512,13 @@ static struct inode *V2_minix_iget(struct inode *inode)
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);