diff options
| author | Dave Martin <Dave.Martin@arm.com> | 2025-07-01 14:56:16 +0100 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2025-07-14 22:27:49 -0700 |
| commit | a55128d392e86507a0e6672ebcdf20d1dd77744b (patch) | |
| tree | 0c536975c4604e080393757fdc4cabdf4a8bef6e | |
| parent | cb32fb722f4be5f5761ff1bf2fcde41de49cf1ef (diff) | |
binfmt_elf: Warn on missing or suspicious regset note names
Now that all regset definitions declare an explicit note name, warn if
the note name is missing when generating a core dump. Simplify the
fallback to always guess "LINUX", which is appropriate for all
Linux-specific notes (i.e., all newly added notes, for a long time
now). The one standard exception (PR_FPREG) will no longer have an
"unexpected" note name overridden, but a warning will still be emitted.
Also warn if the specified note name doesn't match the legacy
pattern -- but don't bother to override the name in this case. This
warning can be removed in future if new note types emerge that require
a specific note name that is not "LINUX".
No functional change, beyond the extra noise in dmesg and not
overriding an unexpected note name for PR_FPREG any more.
Now that all upstream arches are ported to use USER_REGSET_NOTE_TYPE(),
new regsets created by copy-pasting existing code should end up correct
by construction.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Link: https://lore.kernel.org/r/20250701135616.29630-24-Dave.Martin@arm.com
Signed-off-by: Kees Cook <kees@kernel.org>
| -rw-r--r-- | fs/binfmt_elf.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 89063d1d9e9a..92cf005468b5 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1750,8 +1750,13 @@ static int fill_thread_core_info(struct elf_thread_core_info *t, if (is_fpreg) SET_PR_FPVALID(&t->prstatus); - if (!note_name) - note_name = is_fpreg ? NN_PRFPREG : "LINUX"; + /* There should be a note name, but if not, guess: */ + if (WARN_ON_ONCE(!note_name)) + note_name = "LINUX"; + else + /* Warn on non-legacy-compatible names, for now. */ + WARN_ON_ONCE(strcmp(note_name, + is_fpreg ? "CORE" : "LINUX")); __fill_note(&t->notes[note_iter], note_name, note_type, ret, data); |