| From bippy-1.1.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49878: bpf, verifier: Fix memory leak in array reallocation for stack state |
| |
| 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: |
| [<00000000b211474b>] __kmalloc_node_track_caller+0x45/0xc0 |
| [<0000000086712a0b>] krealloc+0x83/0xd0 |
| [<00000000139aab02>] realloc_array+0x82/0xe2 |
| [<00000000b1ca41d1>] grow_stack_state+0xfb/0x186 |
| [<00000000cd6f36d2>] check_mem_access.cold+0x141/0x1341 |
| [<0000000081780455>] do_check_common+0x5358/0xb350 |
| [<0000000015f6b091>] bpf_check.cold+0xc3/0x29d |
| [<000000002973c690>] bpf_prog_load+0x13db/0x2240 |
| [<00000000028d1644>] __sys_bpf+0x1605/0x4ce0 |
| [<00000000053f29bd>] __x64_sys_bpf+0x75/0xb0 |
| [<0000000056fedaf5>] do_syscall_64+0x35/0x80 |
| [<000000002bd58261>] entry_SYSCALL_64_after_hwframe+0x63/0xcd |
| |
| The Linux kernel CVE team has assigned CVE-2022-49878 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.14 with commit c69431aab67a912836e5831f03d99a819c14c9c3 and fixed in 5.15.79 with commit 06615967d4889b08b19ff3dda96e8b131282f73d |
| Issue introduced in 5.14 with commit c69431aab67a912836e5831f03d99a819c14c9c3 and fixed in 6.0.9 with commit 3e210891c4a4c2d858cd6f9f61d5809af251d4df |
| Issue introduced in 5.14 with commit c69431aab67a912836e5831f03d99a819c14c9c3 and fixed in 6.1 with commit 42378a9ca55347102bbf86708776061d8fe3ece2 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2022-49878 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| kernel/bpf/verifier.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/06615967d4889b08b19ff3dda96e8b131282f73d |
| https://git.kernel.org/stable/c/3e210891c4a4c2d858cd6f9f61d5809af251d4df |
| https://git.kernel.org/stable/c/42378a9ca55347102bbf86708776061d8fe3ece2 |
