CVE-2026-98107

Summary

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: fix out-of-bounds write in l2cap_ecred_connect

l2cap_chan_connect() tries to ensure there are no more than L2CAP_ECRED_CONN_SCID_MAX pending ECRED channels, so they fit in the same L2CAP_ECRED_CONN_REQ that l2cap_ecred_connect() constructs.

However, the check only counts deferred channels. If 6 L2CAP sockets are connected at the same time in order DDDDND (D=deferred, N=non-deferred), the last can bump the total to max+1. It results to one __le16 written out of bounds of the scid array, and an invalid ECRED_CONN_REQ being sent.

Fix by leaving room for the non-deferred pending ECRED channels in the counting in l2cap_chan_connect(), so the limit can't be exceeded.

Move counting under same critical section where the channel is added. Although race conditions involving this appear unreachable, it's easier to see.

Also add WARN_ON_ONCE check in l2cap_ecred_defer_connect() to make this less brittle.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxda49b602f7f75ccc91386e1274b3ef71676cd092 < ce0927eb3ee2939fab5ce3f9334bfd2fafb38481affected
LinuxLinuxda49b602f7f75ccc91386e1274b3ef71676cd092 < 6da5c0331fc3ef0c7b8df8269523fc3b2cce1e65affected
LinuxLinuxda49b602f7f75ccc91386e1274b3ef71676cd092 < df8c3af6132640da4788e96a02d653e642059803affected
LinuxLinuxda49b602f7f75ccc91386e1274b3ef71676cd092 < 56c2b5831d39dc84aad2573dc3e197af1a872a05affected
LinuxLinux5.7affected
LinuxLinux0 < 5.7unaffected
LinuxLinux6.12.111 <= 6.12.*unaffected
LinuxLinux6.18.53 <= 6.18.*unaffected
LinuxLinux7.2.7 <= 7.2.*unaffected
LinuxLinux7.3-rc2 <= *unaffected

Weaknesses

References