From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
commit 55cf2f4b945f6a6416cc2524ba740b83cc9af25a upstream.
Most of these sizes and counts are capped at 256MB so the math doesn't
result in an integer overflow. The "relocs" count needs to be checked
as well. Otherwise on 32bit systems the calculation of "full_data"
could be wrong.
full_data = data_len + relocs * sizeof(unsigned long);
Fixes: c995ee28d29d ("binfmt_flat: prevent kernel dammage from corrupted executable headers")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Acked-by: Nicolas Pitre <npitre@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/5be17f6c-5338-43be-91ef-650153b975cb@stanley.mountain
Signed-off-by: Kees Cook <kees@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/binfmt_flat.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -529,7 +529,7 @@ static int load_flat_file(struct linux_b
* 28 bits (256 MB) is way more than reasonable in this case.
* If some top bits are set we have probable binary corruption.
*/
- if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
+ if ((text_len | data_len | bss_len | stack_len | relocs | full_data) >> 28) {
pr_err("bad header\n");
ret = -ENOEXEC;
goto err;
Patches currently in stable-queue which might be from dan.carpenter@xxxxxxxxxx are
queue-5.4/rdma-cxgb4-prevent-potential-integer-overflow-on-32b.patch
queue-5.4/dmaengine-ti-edma-fix-of-node-reference-leaks-in-edm.patch
queue-5.4/binfmt_flat-fix-integer-overflow-bug-on-32-bit-systems.patch
