diff options
| author | Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr> | 2026-08-12 20:30:42 +0000 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2026-08-12 19:53:35 -0600 |
| commit | 6ca662cc71df7eb4eaf1b4bcb07cd3f188ad19f2 (patch) | |
| tree | 886c05e35a4f24e1634a7dd1da1d5bdcfa4bd400 /io_uring | |
| parent | bc0e8faf90e776a2f1f3967a04e8091e6bdb4977 (diff) | |
io_uring/rsrc: reject overflowing regvec bvec byte counts
io_import_reg_vec() converts the estimated number of bio_vec entries
into iovec-sized storage when struct bio_vec is larger than struct
iovec. The conversion still multiplies nr_segs by sizeof(struct
bio_vec) in size_t without checking for overflow.
On 32-bit kernels, a registered buffer large enough to make
io_estimate_bvec_size() return 357913942 segments wraps the byte count
from 0x100000008 to 8. io_vec_realloc() then reserves only the input
iovecs plus one extra slot while io_vec_fill_bvec() writes the full
bio_vec array.
Check both the multiplication and the rounding addition before
deriving the replacement iovec count.
Fixes: b4e41050b212 ("io_uring/rsrc: raise registered buffer 1GB limit")
Assisted-by: Codex:gpt-5
Signed-off-by: Jérémy Jean <Jeremy.Jean@oss.cyber.gouv.fr>
Link: https://patch.msgid.link/20260812203042.720348-1-Jeremy.Jean@oss.cyber.gouv.fr
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/rsrc.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index 8d0f2ee24e0c..98dccefd801b 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -1653,8 +1653,12 @@ int io_import_reg_vec(int ddir, struct iov_iter *iter, if (sizeof(struct bio_vec) > sizeof(struct iovec)) { size_t bvec_bytes; - bvec_bytes = nr_segs * sizeof(struct bio_vec); - nr_segs = (bvec_bytes + sizeof(*iov) - 1) / sizeof(*iov); + if (check_mul_overflow((size_t)nr_segs, sizeof(struct bio_vec), + &bvec_bytes) || + check_add_overflow(bvec_bytes, sizeof(*iov) - 1, + &bvec_bytes)) + return -EOVERFLOW; + nr_segs = bvec_bytes / sizeof(*iov); nr_segs += nr_iovs; } |