CVE-2026-31513 (GCVE-0-2026-31513)
Vulnerability from cvelistv5
Published
2026-04-22 13:54
Modified
2026-10-19 18:45
Severity ?
8.1 (High) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix stack-out-of-bounds read in l2cap_ecred_conn_req Syzbot reported a KASAN stack-out-of-bounds read in l2cap_build_cmd() that is triggered by a malformed Enhanced Credit Based Connection Request. The vulnerability stems from l2cap_ecred_conn_req(). The function allocates a local stack buffer (`pdu`) designed to hold a maximum of 5 Source Channel IDs (SCIDs), totaling 18 bytes. When an attacker sends a request with more than 5 SCIDs, the function calculates `rsp_len` based on this unvalidated `cmd_len` before checking if the number of SCIDs exceeds L2CAP_ECRED_MAX_CID. If the SCID count is too high, the function correctly jumps to the `response` label to reject the packet, but `rsp_len` retains the attacker's oversized value. Consequently, l2cap_send_cmd() is instructed to read past the end of the 18-byte `pdu` buffer, triggering a KASAN panic. Fix this by moving the assignment of `rsp_len` to after the `num_scid` boundary check. If the packet is rejected, `rsp_len` will safely remain 0, and the error response will only read the 8-byte base header from the stack.
References
Impacted products
Vendor Product Version
Linux Linux Version: 935f324e4b2461df2cf7f02b4195082b4304c708
Version: e981a9392800ce2c5bca196a6ab2c55e9370efaa
Version: f3fdf2e7276a3edc5df55454275da20eac186970
Version: c28d2bff70444a85b3b86aaf241ece9408c7858c
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   Linux Linux Version: 6.12.75   ≤
Version: 6.18.16   ≤
Version: 6.19.6   ≤
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