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authorEric Biggers <ebiggers@google.com>2020-08-12 04:35:27 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-08-21 10:48:15 +0300
commit12490f06ef084bc34f5e5dbda104aa034e376f2e (patch)
tree5dd3054311ac6bff53192b9d5f413fa40c098af8
parent3c775629a5ffe3f6305f9a4f53d8167f629435ad (diff)
downloadlinux-12490f06ef084bc34f5e5dbda104aa034e376f2e.tar.xz
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>
-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 b6829d679643..97a6ec14431f 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -471,6 +471,13 @@ 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);
@@ -504,6 +511,13 @@ 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);