CVE-2025-40043
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.29%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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).
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.29% probability · 22th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/0ba68bea1e356f466ad29449938bea12f5f3711f
- https://git.kernel.org/stable/c/74837bca0748763a77f77db47a0bdbe63b347628
- https://git.kernel.org/stable/c/8fcc7315a10a84264e55bb65ede10f0af20a983f
- https://git.kernel.org/stable/c/9c328f54741bd5465ca1dc717c84c04242fac2e1
- https://git.kernel.org/stable/c/bfdda0123dde406dbff62e7e9136037e97998a15
- https://git.kernel.org/stable/c/c395d1e548cc68e84584ffa2e3ca9796a78bf7b9
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.