libelf: Correctly decode ar_mode as octal string
Commit Message
ar_mode is encoded as an octal ascii string, not decimal. Add a new
OCT_FIELD macro to decode it.
Signed-off-by: Mark Wielaard <mark@klomp.org>
---
This was found by the run-ar-N.sh testcase on the try builder.
libelf/ChangeLog | 5 +++++
libelf/elf_begin.c | 25 +++++++++++++++++++++++--
2 files changed, 28 insertions(+), 2 deletions(-)
@@ -1,3 +1,8 @@
+2022-08-28 Mark Wielaard <mark@klomp.org>
+
+ * elf_begin.c (__libelf_next_arhdr_wrlock): Add OCT_FIELD macro,
+ like INT_FIELD but use strtol with octal base 8. Use for ar_mode.
+
2022-08-08 Andreas Schwab <schwab@suse.de>
* elf.h: Update from glibc.
@@ -977,7 +977,8 @@ __libelf_next_arhdr_wrlock (Elf *elf)
atoll depending on the size of the types. We are also prepared
for the case where the whole field in the `struct ar_hdr' is
filled in which case we cannot simply use atol/l but instead have
- to create a temporary copy. */
+ to create a temporary copy. Note that all fields use decimal
+ encoding, except ar_mode which uses octal. */
#define INT_FIELD(FIELD) \
do \
@@ -997,10 +998,30 @@ __libelf_next_arhdr_wrlock (Elf *elf)
} \
while (0)
+#define OCT_FIELD(FIELD) \
+ do \
+ { \
+ char buf[sizeof (ar_hdr->FIELD) + 1]; \
+ const char *string = ar_hdr->FIELD; \
+ if (ar_hdr->FIELD[sizeof (ar_hdr->FIELD) - 1] != ' ') \
+ { \
+ *((char *) mempcpy (buf, ar_hdr->FIELD, sizeof (ar_hdr->FIELD))) \
+ = '\0'; \
+ string = buf; \
+ } \
+ if (sizeof (elf_ar_hdr->FIELD) <= sizeof (long int)) \
+ elf_ar_hdr->FIELD \
+ = (__typeof (elf_ar_hdr->FIELD)) strtol (string, NULL, 8); \
+ else \
+ elf_ar_hdr->FIELD \
+ = (__typeof (elf_ar_hdr->FIELD)) strtoll (string, NULL, 8); \
+ } \
+ while (0)
+
INT_FIELD (ar_date);
INT_FIELD (ar_uid);
INT_FIELD (ar_gid);
- INT_FIELD (ar_mode);
+ OCT_FIELD (ar_mode);
INT_FIELD (ar_size);
if (elf_ar_hdr->ar_size < 0)