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| author | Justin Stitt <justinstitt@google.com> | 2024-04-03 02:52:50 +0300 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2024-04-03 17:57:41 +0300 |
| commit | 2e114248e086fb376405ed3f89b220f8586a2541 (patch) | |
| tree | 3cbcfd5ea628f560c4d4156051ea34fa00509a76 /kernel/bpf/log.c | |
| parent | c53908b254fcf25b05bcdf6634adb36eaccac111 (diff) | |
| download | linux-2e114248e086fb376405ed3f89b220f8586a2541.tar.xz | |
bpf: Replace deprecated strncpy with strscpy
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
bpf sym names get looked up and compared/cleaned with various string
apis. This suggests they need to be NUL-terminated (strncpy() suggests
this but does not guarantee it).
| static int compare_symbol_name(const char *name, char *namebuf)
| {
| cleanup_symbol_name(namebuf);
| return strcmp(name, namebuf);
| }
| static void cleanup_symbol_name(char *s)
| {
| ...
| res = strstr(s, ".llvm.");
| ...
| }
Use strscpy() as this method guarantees NUL-termination on the
destination buffer.
This patch also replaces two uses of strncpy() used in log.c. These are
simple replacements as postfix has been zero-initialized on the stack
and has source arguments with a size less than the destination's size.
Note that this patch uses the new 2-argument version of strscpy
introduced in commit e6584c3964f2f ("string: Allow 2-argument strscpy()").
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Link: https://lore.kernel.org/bpf/20240402-strncpy-kernel-bpf-core-c-v1-1-7cb07a426e78@google.com
Diffstat (limited to 'kernel/bpf/log.c')
| -rw-r--r-- | kernel/bpf/log.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c index 2a243cf37c60..4bd8f17a9f24 100644 --- a/kernel/bpf/log.c +++ b/kernel/bpf/log.c @@ -467,9 +467,9 @@ const char *reg_type_str(struct bpf_verifier_env *env, enum bpf_reg_type type) if (type & PTR_MAYBE_NULL) { if (base_type(type) == PTR_TO_BTF_ID) - strncpy(postfix, "or_null_", 16); + strscpy(postfix, "or_null_"); else - strncpy(postfix, "_or_null", 16); + strscpy(postfix, "_or_null"); } snprintf(prefix, sizeof(prefix), "%s%s%s%s%s%s%s", |