Edward O'Callaghan submitted this change.
dummyflasher.c: Prevent use-after-free bug
The memory for the `status` string is aliased by the `endptr` pointer.
Moreover, `errno` could have been modified by the call to `free()`.
Therefore, only free the former when there are no more uses of either.
Change-Id: I1b56834004fe18918213a7df0a09a8a7ecb56985
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/54909
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>
---
M dummyflasher.c
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/dummyflasher.c b/dummyflasher.c
index 5defec0..560dbdc 100644
--- a/dummyflasher.c
+++ b/dummyflasher.c
@@ -962,12 +962,13 @@
if (status) {
errno = 0;
data->emu_status = strtoul(status, &endptr, 0);
- free(status);
if (errno != 0 || status == endptr) {
+ free(status);
msg_perr("Error: initial status register specified, "
"but the value could not be converted.\n");
return 1;
}
+ free(status);
msg_pdbg("Initial status register is set to 0x%02x.\n",
data->emu_status);
}
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