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| author | Gabriel Krisman Bertazi <krisman@suse.de> | 2023-10-04 20:05:29 -0400 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-10-05 08:38:08 -0600 |
| commit | ab69838e7c75b0edb699c1a8f42752b30333c46f (patch) | |
| tree | eef6edf0b5ffe1ef1d5e74e0f3b1d790071276d0 /io_uring | |
| parent | 922a2c78f13611e2c08fc48f615c0cd367dcb6da (diff) | |
| download | lwn-ab69838e7c75b0edb699c1a8f42752b30333c46f.tar.gz lwn-ab69838e7c75b0edb699c1a8f42752b30333c46f.zip | |
io_uring/kbuf: Fix check of BID wrapping in provided buffers
Commit 3851d25c75ed0 ("io_uring: check for rollover of buffer ID when
providing buffers") introduced a check to prevent wrapping the BID
counter when sqe->off is provided, but it's off-by-one too
restrictive, rejecting the last possible BID (65534).
i.e., the following fails with -EINVAL.
io_uring_prep_provide_buffers(sqe, addr, size, 0xFFFF, 0, 0);
Fixes: 3851d25c75ed ("io_uring: check for rollover of buffer ID when providing buffers")
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20231005000531.30800-2-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/kbuf.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 556f4df25b0f..52dba81c3f50 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -352,7 +352,7 @@ int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe tmp = READ_ONCE(sqe->off); if (tmp > USHRT_MAX) return -E2BIG; - if (tmp + p->nbufs >= USHRT_MAX) + if (tmp + p->nbufs > USHRT_MAX) return -EINVAL; p->bid = tmp; return 0; |