From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Date: Fri, 24 Aug 2018 14:15:35 -0700 From: Kees Cook To: Jens Axboe Cc: syzbot+21cfe1f803e0e158acf1@syzkaller.appspotmail.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] block: Replace bio_check_ro()'s WARN_ON() Message-ID: <20180824211535.GA22251@beast> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii List-ID: As described in commit 96c6a32ccb55a ("include/asm-generic/bug.h: clarify valid uses of WARN()"), this replaces a userspace-reachable WARN_ON() with pr_warn_once(). The reachability is even noted in the existing comment. This appears to be an "expected by unlikely" condition, so getting rid of the WARN_ON() means kernel fuzzers will stop reporting the problem. Additionally un-breaks the error string so it can more easily be found with grep. Reported-by: syzbot+21cfe1f803e0e158acf1@syzkaller.appspotmail.com Cc: Jens Axboe Cc: linux-block@vger.kernel.org Signed-off-by: Kees Cook --- block/blk-core.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index dee56c282efb..470c3cea8cb0 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2166,11 +2166,9 @@ static inline bool bio_check_ro(struct bio *bio, struct hd_struct *part) if (part->policy && (op_is_write(op) && !op_is_flush(op))) { char b[BDEVNAME_SIZE]; - WARN_ONCE(1, - "generic_make_request: Trying to write " - "to read-only block-device %s (partno %d)\n", + /* Older lvm-tools actually triggers this. */ + pr_warn_once("Trying to write to read-only block-device %s (partno %d)\n", bio_devname(bio, b), part->partno); - /* Older lvm-tools actually trigger this */ return false; } -- 2.17.1 -- Kees Cook Pixel Security