diff options
| author | Hou Tao <houtao1@huawei.com> | 2024-10-22 21:01:33 +0800 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2024-10-22 12:56:38 -0700 |
| commit | 1f97c03f43fadc407de5b5cb01c07755053e1c22 (patch) | |
| tree | 788e72b66883e864f7e6292bbed011c1277ec32b | |
| parent | a552e2ef5fd1a6c78267cd4ec5a9b49aa11bbb1c (diff) | |
bpf: Preserve param->string when parsing mount options
In bpf_parse_param(), keep the value of param->string intact so it can
be freed later. Otherwise, the kmalloc area pointed to by param->string
will be leaked as shown below:
unreferenced object 0xffff888118c46d20 (size 8):
comm "new_name", pid 12109, jiffies 4295580214
hex dump (first 8 bytes):
61 6e 79 00 38 c9 5c 7e any.8.\~
backtrace (crc e1b7f876):
[<00000000c6848ac7>] kmemleak_alloc+0x4b/0x80
[<00000000de9f7d00>] __kmalloc_node_track_caller_noprof+0x36e/0x4a0
[<000000003e29b886>] memdup_user+0x32/0xa0
[<0000000007248326>] strndup_user+0x46/0x60
[<0000000035b3dd29>] __x64_sys_fsconfig+0x368/0x3d0
[<0000000018657927>] x64_sys_call+0xff/0x9f0
[<00000000c0cabc95>] do_syscall_64+0x3b/0xc0
[<000000002f331597>] entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fixes: 6c1752e0b6ca ("bpf: Support symbolic BPF FS delegation mount options")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20241022130133.3798232-1-houtao@huaweicloud.com
| -rw-r--r-- | kernel/bpf/inode.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index d8fc5eba529d..9aaf5124648b 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -880,7 +880,7 @@ static int bpf_parse_param(struct fs_context *fc, struct fs_parameter *param) const struct btf_type *enum_t; const char *enum_pfx; u64 *delegate_msk, msk = 0; - char *p; + char *p, *str; int val; /* ignore errors, fallback to hex */ @@ -911,7 +911,8 @@ static int bpf_parse_param(struct fs_context *fc, struct fs_parameter *param) return -EINVAL; } - while ((p = strsep(¶m->string, ":"))) { + str = param->string; + while ((p = strsep(&str, ":"))) { if (strcmp(p, "any") == 0) { msk |= ~0ULL; } else if (find_btf_enum_const(info.btf, enum_t, enum_pfx, p, &val)) { |