If iov_offset is non-zero, then we need to consider iov_offset in length
calculation, otherwise we might pass smaller IOs such as 512 bytes, in
below scenario[1].
This issue is reproducible using lib-uring test/fixed-seg.c application
with fixed buffer on a 512 LBA formatted device.
Fixes â3639f96f24a121ec9f037981b81daf5a8d60a
[1]
At present we pass the alignment check,
for 512 LBA formatted devices, len_mask = 511
when IO is smaller, i->count = 512
has an offset, i->io_offset = 3584
with bvec values, bvec->bv_offset = 256, bvec->bv_len = 3840.
In short, the first 256 bytes are in the current page,
next 256 bytes are in the second page.
Ideally we expect to fail the IO.
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com>
---
lib/iov_iter.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index bc9391e55d57..9ce83ab71bac 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -820,7 +820,7 @@ static bool iov_iter_aligned_bvec(const struct iov_iter *i, unsigned addr_mask,
size_t size = i->count;
do {
- size_t len = bvec->bv_len;
+ size_t len = bvec->bv_len - skip;
if (len > size)
len = size;
base-commit: 02ddfb981de88a2c15621115dd7be2431252c568
--
2.43.0