binfmt_elf_fdpic: fix AUXV size calculation for ELF_HWCAP3 and ELF_HWCAP4

Commit 4e6e8c2b757f ("binfmt_elf: Wire up AT_HWCAP3 at AT_HWCAP4") added
support for AT_HWCAP3 and AT_HWCAP4, but it missed updating the AUX
vector size calculation in create_elf_fdpic_tables() and
AT_VECTOR_SIZE_BASE in include/linux/auxvec.h.

Similar to the fix for AT_HWCAP2 in commit c6a09e342f8e ("binfmt_elf_fdpic:
fix AUXV size calculation when ELF_HWCAP2 is defined"), this omission
leads to a mismatch between the reserved space and the actual number of
AUX entries, eventually triggering a kernel BUG_ON(csp != sp).

Fix this by incrementing nitems when ELF_HWCAP3 or ELF_HWCAP4 are
defined and updating AT_VECTOR_SIZE_BASE.

Cc: Mark Brown <broonie@kernel.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@futurfusion.io>
Fixes: 4e6e8c2b757f ("binfmt_elf: Wire up AT_HWCAP3 at AT_HWCAP4")
Signed-off-by: Andrei Vagin <avagin@google.com>
Link: https://patch.msgid.link/20260217180108.1420024-2-avagin@google.com
Signed-off-by: Kees Cook <kees@kernel.org>

diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c
index 95b1d085213542125803dbda5ab9005b024e67f8..95b65aab7daa973c8d9ce4960a52f33dac052752 100644 (file)
--- a/fs/binfmt_elf_fdpic.c
+++ b/fs/binfmt_elf_fdpic.c
@@ -595,6 +595,12 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 #ifdef ELF_HWCAP2
        nitems++;
 #endif
+#ifdef ELF_HWCAP3
+       nitems++;
+#endif
+#ifdef ELF_HWCAP4
+       nitems++;
+#endif
 
        csp = sp;
        sp -= nitems * 2 * sizeof(unsigned long);

diff --git a/include/linux/auxvec.h b/include/linux/auxvec.h
index 407f7005e6d60af23fca5ae876147e1d1b5f5c57..8bcb9b72626286f5d38e658e3b92c84a154917cf 100644 (file)
--- a/include/linux/auxvec.h
+++ b/include/linux/auxvec.h
@@ -4,6 +4,6 @@
 
 #include <uapi/linux/auxvec.h>
 
-#define AT_VECTOR_SIZE_BASE 22 /* NEW_AUX_ENT entries in auxiliary table */
+#define AT_VECTOR_SIZE_BASE 24 /* NEW_AUX_ENT entries in auxiliary table */
   /* number of "#define AT_.*" above, minus {AT_NULL, AT_IGNORE, AT_NOTELF} */
 #endif /* _LINUX_AUXVEC_H */