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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
io_uring/kbuf: check if target buffer list is still legacy on recycle
There's a gap between when the buffer was grabbed and when it
potentially gets recycled, where if the list is empty, someone could've
upgraded it to a ring provided type. This can happen if the request
is forced via io-wq. The legacy recycling is missing checking if the
buffer_list still exists, and if it's of the correct type. Add those
checks.
Cc: stable@vger.kernel.org
Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers")
Reported-by: Keenan Dong <keenanat2000@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
+11
-2
+11
-2
io_uring/kbuf.c
+11
-2
io_uring/kbuf.c
···
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buf = req->kbuf;
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bl = io_buffer_get_list(ctx, buf->bgid);
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-
list_add(&buf->list, &bl->buf_list);
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-
bl->nbufs++;
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+
/*
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* If the buffer list was upgraded to a ring-based one, or removed,
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* while the request was in-flight in io-wq, drop it.
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*/
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if (bl && !(bl->flags & IOBL_BUF_RING)) {
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list_add(&buf->list, &bl->buf_list);
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bl->nbufs++;
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} else {
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kfree(buf);
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}
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req->flags &= ~REQ_F_BUFFER_SELECTED;
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req->kbuf = NULL;
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io_ring_submit_unlock(ctx, issue_flags);
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return true;