6.6-stable review patch. If anyone has any objections, please let me know.
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From: Gabriel Krisman Bertazi krisman@suse.de
[ Upstream commit f74c746e476b9dad51448b9a9421aae72b60e25f ]
nbufs tracks the number of buffers and not the last bgid. In 16-bit, we have 2^16 valid buffers, but the check mistakenly rejects the last bid. Let's fix it to make the interface consistent with the documentation.
Fixes: ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS") Signed-off-by: Gabriel Krisman Bertazi krisman@suse.de Link: https://lore.kernel.org/r/20231005000531.30800-3-krisman@suse.de Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- io_uring/kbuf.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index 74a4f9600642f..f6e5ae026e4be 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -19,12 +19,15 @@
#define BGID_ARRAY 64
+/* BIDs are addressed by a 16-bit field in a CQE */ +#define MAX_BIDS_PER_BGID (1 << 16) + struct io_provide_buf { struct file *file; __u64 addr; __u32 len; __u32 bgid; - __u16 nbufs; + __u32 nbufs; __u16 bid; };
@@ -289,7 +292,7 @@ int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return -EINVAL;
tmp = READ_ONCE(sqe->fd); - if (!tmp || tmp > USHRT_MAX) + if (!tmp || tmp > MAX_BIDS_PER_BGID) return -EINVAL;
memset(p, 0, sizeof(*p)); @@ -332,7 +335,7 @@ int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe return -EINVAL;
tmp = READ_ONCE(sqe->fd); - if (!tmp || tmp > USHRT_MAX) + if (!tmp || tmp > MAX_BIDS_PER_BGID) return -E2BIG; p->nbufs = tmp; p->addr = READ_ONCE(sqe->addr); @@ -352,7 +355,7 @@ 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 > MAX_BIDS_PER_BGID) return -EINVAL; p->bid = tmp; return 0;