| Message ID | 20220303081800.82653-1-ytcoode@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf-next] bpf: Replace strncpy() with strscpy_pad() | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Clearly marked for bpf-next |
| netdev/fixes_present | success | Fixes tag not required for -next series |
| netdev/subject_prefix | success | Link |
| netdev/cover_letter | success | Single patches do not need cover letters |
| netdev/patch_count | success | Link |
| netdev/header_inline | success | No static functions without inline keyword in header files |
| netdev/build_32bit | success | Errors and warnings before: 9 this patch: 9 |
| netdev/cc_maintainers | success | CCed 10 of 10 maintainers |
| netdev/build_clang | success | Errors and warnings before: 18 this patch: 18 |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/verify_fixes | success | No Fixes tag |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 14 this patch: 14 |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 14 lines checked |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/source_inline | success | Was 0 now: 0 |
| bpf/vmtest-bpf-next-PR | success | PR summary |
| bpf/vmtest-bpf-next | success | VM_Test |
On 3/3/22 12:18 AM, Yuntao Wang wrote: > Using strncpy() on NUL-terminated strings is considered deprecated[1], > replace it with strscpy_pad(). > > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings > > Signed-off-by: Yuntao Wang <ytcoode@gmail.com> > --- > kernel/bpf/helpers.c | 8 +------- > 1 file changed, 1 insertion(+), 7 deletions(-) > > diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c > index ae64110a98b5..d03b28761a67 100644 > --- a/kernel/bpf/helpers.c > +++ b/kernel/bpf/helpers.c > @@ -225,13 +225,7 @@ BPF_CALL_2(bpf_get_current_comm, char *, buf, u32, size) > if (unlikely(!task)) > goto err_clear; > > - strncpy(buf, task->comm, size); > - > - /* Verifier guarantees that size > 0. For task->comm exceeding > - * size, guarantee that buf is %NUL-terminated. Unconditionally > - * done here to save the size test. > - */ > - buf[size - 1] = 0; > + strscpy_pad(buf, task->comm, size); The precise replacement should be strscpy(...), right? I am not sure whether we want to do pad here or not, probably not as it is mostly used by user space for string copy/print and we don't have cases demanding padding yet. Please keep the comment /* Verifier guarantees that size > 0 */ this is important as strscpy will not do anything if size == 0. > return 0; > err_clear: > memset(buf, 0, size);
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index ae64110a98b5..d03b28761a67 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -225,13 +225,7 @@ BPF_CALL_2(bpf_get_current_comm, char *, buf, u32, size) if (unlikely(!task)) goto err_clear; - strncpy(buf, task->comm, size); - - /* Verifier guarantees that size > 0. For task->comm exceeding - * size, guarantee that buf is %NUL-terminated. Unconditionally - * done here to save the size test. - */ - buf[size - 1] = 0; + strscpy_pad(buf, task->comm, size); return 0; err_clear: memset(buf, 0, size);
Using strncpy() on NUL-terminated strings is considered deprecated[1], replace it with strscpy_pad(). [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings Signed-off-by: Yuntao Wang <ytcoode@gmail.com> --- kernel/bpf/helpers.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-)