Linux vulnerability

What happened

In the Linux kernel, the following vulnerability has been resolved: start_kernel: Add __no_stack_protector function attribute Back during the discussion of commit a9a3ed1eff36 ("x86: Fix early boot crash on gcc-10, third try") we discussed the need for a function attribute to control the omission of stack protectors on a per-function basis; at the time Clang had support for no_stack_protector but GCC did not. This was fixed in gcc-11. Now that the function attribute is available, let's start using it. Callers of boot_init_stack_canary need to use this function attribute unless they're compiled with -fno-stack-protector, otherwise the canary stored in the stack slot of the caller will differ upon the call to boot_init_stack_canary. This will lead to a call to __stack_chk_fail() then panic.

Affected versions

Linux: 420594296838fdc9a674470d710cda7d1487f9f4 through before 5a7e8f89cdee16db705905a5b1ce2100b13dd63e (git); 420594296838fdc9a674470d710cda7d1487f9f4 through before 25e73018b4093e0cfbcec5dc4a4bb86d0b69ed56 (git); 420594296838fdc9a674470d710cda7d1487f9f4 through before 514ca14ed5444b911de59ed3381dfd195d99fe4b (git); 2.6.30 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.