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CVE-2025-40043

net: nfc: nci: Add parameter validation for packet data PUBLISHED

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: net: nfc: nci: Add parameter validation for packet data Syzbot reported an uninitialized value bug in nci_init_req, which was introduced by commit 5aca7966d2a7 ("Merge tag 'perf-tools-fixes-for-v6.17-2025-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools"). This bug arises due to very limited and poor input validation that was done at nic_valid_size(). This validation only validates the skb->len (directly reflects size provided at the userspace interface) with the length provided in the buffer itself (interpreted as NCI_HEADER). This leads to the processing of memory content at the address assuming the correct layout per what opcode requires there. This leads to the accesses to buffer of `skb_buff->data` which is not assigned anything yet. Following the same silent drop of packets of invalid sizes at `nic_valid_size()`, add validation of the data in the respective handlers and return error values in case of failure. Release the skb if error values are returned from handlers in `nci_nft_packet` and effectively do a silent drop Possible TODO: because we silently drop the packets, the call to `nci_request` will be waiting for completion of request and will face timeouts. These timeouts can get excessively logged in the dmesg. A proper handling of them may require to export `nci_request_cancel` (or propagate error handling from the nft packets handlers).

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 8fcc7315a10a84264e55bb65ede10f0af20a983f; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before bfdda0123dde406dbff62e7e9136037e97998a15; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 0ba68bea1e356f466ad29449938bea12f5f3711f; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 74837bca0748763a77f77db47a0bdbe63b347628; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before c395d1e548cc68e84584ffa2e3ca9796a78bf7b9; affected 6a2968aaf50c7a22fced77a5e24aa636281efca8 before 9c328f54741bd5465ca1dc717c84c04242fac2e1
Linux / Linuxaffected 3.2; unaffected 0 before 3.2; unaffected 5.15.195 through 5.15.*; unaffected 6.1.156 through 6.1.*; unaffected 6.6.112 through 6.6.*; unaffected 6.12.53 through 6.12.*; unaffected 6.17.3 through 6.17.*; unaffected 6.18 through *

CWE

No CWE identifiers supplied.

References