Messages in this thread Patch in this message | | | Date | Fri, 24 Aug 2018 14:15:35 -0700 | From | Kees Cook <> | Subject | [PATCH] block: Replace bio_check_ro()'s WARN_ON() |
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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 <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- 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
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