On 06/10/24 12:28, Suraj Sonawane wrote:
On 04/10/24 20:03, John Garry wrote:
On 04/10/2024 15:10, SurajSonawane2415 wrote:
Explaination of how bio could be used uninitialized in this function:
In the function blk_rq_prep_clone, the variable bio is declared but
can remain uninitialized
if the allocation with bio_alloc_clone fails. This can lead to
undefined behavior when the
function attempts to free bio in the error handling section using
bio_put(bio).
By initializing bio to NULL at declaration, we ensure that the
cleanup code will only
interact with bio if it has been successfully allocated.
What about if rq_src->bio is NULL for blk_rq_prep_clone() ->
__rq_for_each_bio(,rq_src):
#define __rq_for_each_bio(_bio, rq) \
if ((rq->bio)) \
for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
Then I don't think bio it get init'ed. Whether this is possible
(rq_src->bio is NULL) is another question.
Hi Keith,
I realized I mistakenly addressed my reply to you as "Keith" in this
message. Apologies for the confusion. Thank you again for your input!
You're right to bring this up. If rq_src->bio is NULL, the
__rq_for_each_bio macro will skip the loop, meaning the bio variable
won't be used at all. So, even if bio isn’t initialized, it won't cause
any issues in that case.
Thanks for pointing that out.
Best regards,
Suraj
Best regards,
Suraj
