On Mon, Apr 29, 2024 at 05:21:28PM +0000, Allen Pais wrote:
> Introduce the capability to dynamically configure the maximum file
> note size for ELF core dumps via sysctl. This enhancement removes
> the previous static limit of 4MB, allowing system administrators to
> adjust the size based on system-specific requirements or constraints.
Under what conditions is this actually needed?
> [...]
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index 81cc974913bb..80cdc37f2fa2 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -63,6 +63,7 @@
> #include <linux/mount.h>
> #include <linux/userfaultfd_k.h>
> #include <linux/pid.h>
> +#include <linux/coredump.h>
>
> #include "../lib/kstrtox.h"
>
> @@ -1623,6 +1624,13 @@ static struct ctl_table kern_table[] = {
> .mode = 0644,
> .proc_handler = proc_dointvec,
> },
> + {
> + .procname = "max_file_note_size",
> + .data = &max_file_note_size,
> + .maxlen = sizeof(unsigned int),
> + .mode = 0644,
> + .proc_handler = proc_dointvec,
> + },
Please don't add new sysctls to kernel/sysctl.c. Put this in fs/coredump.c
instead, and name it "core_file_note_size_max". (A "max" suffix is more
common than prefixes, and I'd like it clarified that it relates to the
coredumper with the "core" prefix that match the other coredump sysctls.
-Kees
--
Kees Cook
