Description

In the Linux kernel, the following vulnerability has been resolved: bpf, verifier: Fix memory leak in array reallocation for stack state If an error (NULL) is returned by krealloc(), callers of realloc_array() were setting their allocation pointers to NULL, but on error krealloc() does not touch the original allocation. This would result in a memory resource leak. Instead, free the old allocation on the error handling path. The memory leak information is as follows as also reported by Zhengchao: unreferenced object 0xffff888019801800 (size 256): comm "bpf_repo", pid 6490, jiffies 4294959200 (age 17.170s) hex dump (first 32 bytes): 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 00 ................ backtrace: [] __kmalloc_node_track_caller+0x45/0xc0 [] krealloc+0x83/0xd0 [] realloc_array+0x82/0xe2 [] grow_stack_state+0xfb/0x186 [] check_mem_access.cold+0x141/0x1341 [] do_check_common+0x5358/0xb350 [] bpf_check.cold+0xc3/0x29d [] bpf_prog_load+0x13db/0x2240 [] __sys_bpf+0x1605/0x4ce0 [] __x64_sys_bpf+0x75/0xb0 [] do_syscall_64+0x35/0x80 [] entry_SYSCALL_64_after_hwframe+0x63/0xcd