[Crash-utility] [PATCH] fix eheader overflow
crash-utility live session fails solid with a SEGV, where it seems
that with some (new ?) Kernels and configurations /proc/kcore
exposes a first “Note” program-header along with a big number of
other headers (particularly when direct-map area generated from
physical memory map have a lot of entries), causing eheader[]
overflow (a stack underflow in fact since it is an automatic
variable!) because the whole size exceeds MAX_KCORE_ELF_HEADER_SIZE.
This problem still occur with latest utility version, and the
following patch has been proven to fix.
Signed-off-by: Bruno Faccini <bfaccini(a)nvidia.com>
diff --git a/netdump.c b/netdump.c
index 452ef72..7697613 100644
--- a/netdump.c
+++ b/netdump.c
@@ -4664,7 +4664,12 @@ proc_kcore_init_32(FILE *fp, int kcore_fd)
clean_exit(1);
}
- BCOPY(&eheader[0], &pkd->elf_header[0], pkd->header_size);
+ if (read(fd, pkd->elf_header, pkd->header_size) != pkd->header_size) {
+ sprintf(buf, "/proc/kcore: read");
+ perror(buf);
+ goto bailout;
+ }
+
pkd->notes32 = (Elf32_Phdr *)&pkd->elf_header[elf32->e_phoff];
pkd->load32 = pkd->notes32 + 1;
pkd->flags |= KCORE_ELF32;
@@ -4738,7 +4743,12 @@ proc_kcore_init_64(FILE *fp, int kcore_fd)
clean_exit(1);
}
- BCOPY(&eheader[0], &pkd->elf_header[0], pkd->header_size);
+ if (read(fd, pkd->elf_header, pkd->header_size) != pkd->header_size) {
+ sprintf(buf, "/proc/kcore: read");
+ perror(buf);
+ goto bailout;
+ }
+
pkd->notes64 = (Elf64_Phdr *)&pkd->elf_header[elf64->e_phoff];
pkd->load64 = pkd->notes64 + 1;
pkd->flags |= KCORE_ELF64;