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authorHou Tao <houtao1@huawei.com>2024-10-22 21:01:33 +0800
committerAndrii Nakryiko <andrii@kernel.org>2024-10-22 12:56:38 -0700
commit1f97c03f43fadc407de5b5cb01c07755053e1c22 (patch)
tree788e72b66883e864f7e6292bbed011c1277ec32b /kernel/bpf
parenta552e2ef5fd1a6c78267cd4ec5a9b49aa11bbb1c (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
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/inode.c5
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(&param->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)) {