From: Amir Goldstein <amir73il@gmail.com> mainline inclusion from mainline-v6.9-rc1 commit 77a28aa476873048024ad56daf8f4f17d58ee48e category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBHLU4 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- syzbot hit an assertion in copy up data loop which looks like it is the result of a lower file whose size is being changed underneath overlayfs. This type of use case is documented to cause undefined behavior, so returning EIO error for the copy up makes sense, but it should not be causing a WARN_ON assertion. Reported-and-tested-by: syzbot+3abd99031b42acf367ef@syzkaller.appspotmail.com Fixes: ca7ab482401c ("ovl: add permission hooks outside of do_splice_direct()") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- fs/overlayfs/copy_up.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index b6573fa863e9..5da41eba056d 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -234,11 +234,11 @@ static int ovl_verify_area(loff_t pos, loff_t pos2, loff_t len, loff_t totlen) { loff_t tmp; - if (WARN_ON_ONCE(pos != pos2)) + if (pos != pos2) return -EIO; - if (WARN_ON_ONCE(pos < 0 || len < 0 || totlen < 0)) + if (pos < 0 || len < 0 || totlen < 0) return -EIO; - if (WARN_ON_ONCE(check_add_overflow(pos, len, &tmp))) + if (check_add_overflow(pos, len, &tmp)) return -EIO; return 0; } -- 2.39.2