diff options
| 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/core.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/core.c')
| -rw-r--r-- | kernel/bpf/core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index ab400cdd7d7a..ae406a2814db 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -747,7 +747,7 @@ const char *__bpf_address_lookup(unsigned long addr, unsigned long *size, unsigned long symbol_start = ksym->start; unsigned long symbol_end = ksym->end; - strncpy(sym, ksym->name, KSYM_NAME_LEN); + strscpy(sym, ksym->name, KSYM_NAME_LEN); ret = sym; if (size) @@ -813,7 +813,7 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type, if (it++ != symnum) continue; - strncpy(sym, ksym->name, KSYM_NAME_LEN); + strscpy(sym, ksym->name, KSYM_NAME_LEN); *value = ksym->start; *type = BPF_SYM_ELF_TYPE; |