CVE-2024-26840

In the Linux kernel, the following vulnerability has been resolved: cachefiles: fix memory leak in cachefiles_add_cache() The following memory leak was reported after unbinding /dev/cachefiles: ================================================================== unreferenced object 0xffff9b674176e3c0 (size 192): comm "cachefilesd2", pid 680, jiffies 4294881224 hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc ea38a44b): [ ] kmem_cache_alloc+0x2d5/0x370 [ ] prepare_creds+0x26/0x2e0 [ ] cachefiles_determine_cache_security+0x1f/0x120 [ ] cachefiles_add_cache+0x13c/0x3a0 [ ] cachefiles_daemon_write+0x146/0x1c0 [ ] vfs_write+0xcb/0x520 [ ] ksys_write+0x69/0xf0 [ ] do_syscall_64+0x72/0x140 [ ] entry_SYSCALL_64_after_hwframe+0x6e/0x76 ================================================================== Put the reference count of cache_cred in cachefiles_daemon_unbind() to fix the problem. And also put cache_cred in cachefiles_add_cache() error branch to avoid memory leaks.