In the Linux kernel, the following vulnerability has been resolved: exec: don't WARN for racy path_noexec check Both i_mode and noexec checks wrapped in WARN_ON stem from an artifact of the previous implementation. They used to legitimately check for the condition, but that got moved up in two commits: 633fb6ac3980 ("exec: move S_ISREG() check earlier") 0fd338b2d2cd ("exec: move path_noexec() check earlier") Instead of being removed said checks are WARN_ON'ed instead, which has some debug value. However, the spurious path_noexec check is racy, resulting in unwarranted warnings should someone race with setting the noexec flag. One can note there is more to perm-checking whether execve is allowed and none of the conditions are guaranteed to still hold after they were tested for. Additionally this does not validate whether the code path did any perm checking to begin with -- it will pass if the inode happens to be regular. Keep the redundant path_noexec() check even though it's mindless nonsense checking for guarantee that isn't given so drop the WARN. Reword the commentary and do small tidy ups while here. [brauner: keep redundant path_noexec() check]
https://git.kernel.org/stable/c/d62ba2a5536df83473a2ac15ab302258e3845251
https://git.kernel.org/stable/c/c9b77438077d5a20c79ead95bcdaf9bd4797baaf
https://git.kernel.org/stable/c/b8b0e9650eeb6637b4e1cf3d6aaf0e96f87862e7
https://git.kernel.org/stable/c/b723f96407a0a078cf75970e4dbf16b46d286a61
https://git.kernel.org/stable/c/0d196e7589cefe207d5d41f37a0a28a1fdeeb7c6
https://git.kernel.org/stable/c/0d16f53c91111cec914f0811fcc526a2ba77b20d
https://git.kernel.org/stable/c/0bdf77be2330062b3a64f2bec39f62ab874a6796