liburing.h: fix integer overflow in recvmsg_cmsg_nexthdr#1587
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rootvector2 wants to merge 1 commit into
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liburing.h: fix integer overflow in recvmsg_cmsg_nexthdr#1587rootvector2 wants to merge 1 commit into
rootvector2 wants to merge 1 commit into
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io_uring_recvmsg_cmsg_nexthdr() advances cmsg by CMSG_ALIGN(cmsg_len) before any bounds check. A cmsg_len near SIZE_MAX makes CMSG_ALIGN() wrap to a small value, or the pointer addition wrap past the control buffer, so the following '> end' checks pass and the helper returns a wild cmsg whose cmsg_len is then dereferenced. Bound the aligned length against the remaining control space before advancing, matching the overflow hardening already done in recvmsg_validate. Signed-off-by: rootvector2 <dxbnaveed.k@gmail.com>
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Noticed recvmsg_cmsg_nexthdr advances cmsg by CMSG_ALIGN(cmsg_len) before any bounds check. A cmsg_len near SIZE_MAX makes the align wrap to a small value, or the pointer add wrap past the control buffer, so the '> end' checks pass and the wild cmsg gets returned and dereferenced. Bound the aligned length against the remaining control space before advancing, the same way the recent recvmsg_validate fix did.