* Arnd Bergmann <arnd@xxxxxxxx> wrote: > gcc-8 warns about using strncpy() with the source size as the limit: > > fs/exec.c:1223:32: error: argument to 'sizeof' in 'strncpy' call is the same expression as the source; did you mean to use the size of the destination? [-Werror=sizeof-pointer-memaccess] > > This is indeed slightly suspicious, as it protects us from source > arguments without NUL-termination, but does not guarantee that the > destination is terminated. > > This keeps the strncpy() to ensure we have properly padded target buffer, > but ensures that we use the correct length, by passing the actual length > of the destination buffer as well as adding a build-time check to ensure > it is exactly TASK_COMM_LEN. There are only 23 callsights which I all > reviewed to ensure this is currently the case. We could get away with > doing only the check or passing the right length, but it doesn't hurt > to do both. > > Suggested-by: Kees Cook <keescook@xxxxxxxxxxxx> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Looks useful. Acked-by: Ingo Molnar <mingo@xxxxxxxxxx> Thanks, Ingo
