TWxSoftware/twx-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

io_uring/kbuf: reallocate buf lists on upgrade

Browse Source 
commit 8802766324 upstream.

IORING_REGISTER_PBUF_RING can reuse an old struct io_buffer_list if it
was created for legacy selected buffer and has been emptied. It violates
the requirement that most of the field should stay stable after publish.
Always reallocate it instead.

Cc: stable@vger.kernel.org
Reported-by: Pumpkin Chang <pumpkin@devco.re>
Fixes: 2fcabce2d7 ("io_uring: disallow mixed provided buffer group registrations")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pavel Begunkov
2025-02-12 13:46:46 +00:00
committed by Greg Kroah-Hartman
parent 13129b1fbf
commit 7d0dc28dae
1 changed files with 11 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files
io_uring/kbuf.c
+11 -4
View File
@@ -420,6 +420,12 @@ void io_destroy_buffers(struct io_ring_ctx *ctx)
}
}
static void io_destroy_bl(struct io_ring_ctx *ctx, struct io_buffer_list *bl)
{
xa_erase(&ctx->io_bl_xa, bl->bgid);
io_put_bl(ctx, bl);
}
int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_provide_buf *p = io_kiocb_to_cmd(req, struct io_provide_buf);
@@ -717,12 +723,13 @@ int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg)
/* if mapped buffer ring OR classic exists, don't allow */
if (bl->flags & IOBL_BUF_RING || !list_empty(&bl->buf_list))
return -EEXIST;
} else {
free_bl = bl = kzalloc(sizeof(*bl), GFP_KERNEL);
if (!bl)
return -ENOMEM;
io_destroy_bl(ctx, bl);
}
free_bl = bl = kzalloc(sizeof(*bl), GFP_KERNEL);
if (!bl)
return -ENOMEM;
if (!(reg.flags & IOU_PBUF_RING_MMAP))
ret = io_pin_pbuf_ring(&reg, bl);
else