Paper/Archive/CVE-2026-43185

CVE-2026-43185

Linux Linux — ksmbd: fix signededness bug in smb_direct_prepare_negotiation()

Description · from the CVE record

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix signededness bug in smb_direct_prepare_negotiation() smb_direct_prepare_negotiation() casts an unsigned __u32 value from sp->max_recv_size and req->preferred_send_size to a signed int before computing min_t(int, ...). A maliciously provided preferred_send_size of 0x80000000 will return as smaller than max_recv_size, and then be used to set the maximum allowed alowed receive size for the next message. By sending a second message with a large value (>1420 bytes) the attacker can then achieve a heap buffer overflow. This fix replaces min_t(int, ...) with min_t(u32)

Affected

ProductAffectedFixed inSource
Linux0626e6641f6b467447c81dd7678a69c66f7746cf – < 56eab82fa6fb5ca024b0514e249d40d9b23ee5a756eab82fa6fb5ca024b0514e249d40d9b23ee5a7CNA
Linux0626e6641f6b467447c81dd7678a69c66f7746cf – < a110dbe928561d440e9e117d17331139a0bedacea110dbe928561d440e9e117d17331139a0bedaceCNA
Linux0626e6641f6b467447c81dd7678a69c66f7746cf – < ceae058eb707ddd0d68f0872f9d9f23b7c30c37bceae058eb707ddd0d68f0872f9d9f23b7c30c37bCNA
Linux0626e6641f6b467447c81dd7678a69c66f7746cf – < 55abc475d096da4a5356b6efb0cfdc6156bc155055abc475d096da4a5356b6efb0cfdc6156bc1550CNA
Linux0626e6641f6b467447c81dd7678a69c66f7746cf – < 6b4f875aac344cdd52a1f34cc70ed2f874a657576b4f875aac344cdd52a1f34cc70ed2f874a65757CNA
Linux5.15–CNA

Scores by source

Linux (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

refgit.kernel.org/stable/c/56eab82fa6fb5ca024b0514e249d40d9b23ee5a7refgit.kernel.org/stable/c/a110dbe928561d440e9e117d17331139a0bedacerefgit.kernel.org/stable/c/ceae058eb707ddd0d68f0872f9d9f23b7c30c37brefgit.kernel.org/stable/c/55abc475d096da4a5356b6efb0cfdc6156bc1550refgit.kernel.org/stable/c/6b4f875aac344cdd52a1f34cc70ed2f874a65757