diff options
| author | Konstantin Belousov <kib@FreeBSD.org> | 2024-02-10 01:36:58 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2024-02-11 03:37:12 +0000 |
| commit | 29d4f8bfc642f0196c27eb469ea7eb326ff529d1 (patch) | |
| tree | 5805267a89b0f265002b94f86d8ce02939d5abb3 | |
| parent | a67edb5616c1514726ac1c8596ce0ddc2771e2fa (diff) | |
| download | src-29d4f8bfc642f0196c27eb469ea7eb326ff529d1.tar.gz src-29d4f8bfc642f0196c27eb469ea7eb326ff529d1.zip | |
ELF note parser: provide more info on failure
Print reasons when parser declined to parse notes, due to mis-alignment,
invalid length, or too many notes (the later typically means that there
is a loop). Also increase the loop limit to 4096, which gives enough
iterations for notes to fill whole notes' page.
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
| -rw-r--r-- | sys/kern/imgact_elf.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c index 49dcae050d76..8f85a4f5e18a 100644 --- a/sys/kern/imgact_elf.c +++ b/sys/kern/imgact_elf.c @@ -2709,6 +2709,7 @@ __elfN(note_procstat_auxv)(void *arg, struct sbuf *sb, size_t *sizep) } } +#define MAX_NOTES_LOOP 4096 bool __elfN(parse_notes)(struct image_params *imgp, Elf_Note *checknote, const char *note_vendor, const Elf_Phdr *pnote, @@ -2748,9 +2749,15 @@ __elfN(parse_notes)(struct image_params *imgp, Elf_Note *checknote, pnote->p_offset + pnote->p_filesz); buf = NULL; } - for (i = 0; i < 100 && note >= note0 && note < note_end; i++) { - if (!aligned(note, Elf32_Addr) || (const char *)note_end - - (const char *)note < sizeof(Elf_Note)) { + for (i = 0; i < MAX_NOTES_LOOP && note >= note0 && note < note_end; + i++) { + if (!aligned(note, Elf32_Addr)) { + uprintf("Unaligned ELF note\n"); + goto retf; + } + if ((const char *)note_end - (const char *)note < + sizeof(Elf_Note)) { + uprintf("ELF note to short\n"); goto retf; } if (note->n_namesz != checknote->n_namesz || @@ -2770,6 +2777,8 @@ nextnote: roundup2(note->n_namesz, ELF_NOTE_ROUNDSIZE) + roundup2(note->n_descsz, ELF_NOTE_ROUNDSIZE)); } + if (i >= MAX_NOTES_LOOP) + uprintf("ELF note parser reached %d notes\n", i); retf: res = false; ret: |