From c8dd1aa0274d8ad3df82ec1b064065f410ce99ed Mon Sep 17 00:00:00 2001 From: Leizhen Zhang Date: Mon, 5 Oct 2026 03:57:29 -0500 Subject: [PATCH] gen_init_cpio: stop parsing on lines with a missing argument list When a line in the cpio list consists of a file type followed only by whitespace and no newline (e.g. "slink " as the last line of the file), strtok(NULL, "\n") returns NULL. main() prints an error and sets ec, but then carries on and passes the NULL args pointer to the type handler, which hands it to sscanf() and crashes: AddressSanitizer: SEGV on unknown address 0x000000000000 #4 __isoc99_sscanf #5 cpio_mkslink_line usr/gen_init_cpio.c:169 Break out of the loop as is already done for the other format error, so that the error is reported and gen_init_cpio exits with a failure status. Found by fuzzing gen_init_cpio built with ASan/UBSan. Reproducer: printf 'slink ' > list && usr/gen_init_cpio list Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Assisted-by: Claude:claude-opus-5-5 ASan UBSan Signed-off-by: Leizhen Zhang Link: https://patch.msgid.link/20261005085729.872402-1-lzsx618@gmail.com Signed-off-by: Nathan Chancellor --- scripts/gen_init_cpio.c | 1 + 1 file changed, 1 insertion(+) diff --git a/scripts/gen_init_cpio.c b/scripts/gen_init_cpio.c index b7296edc6626..0f0c61ec21ca 100644 --- a/scripts/gen_init_cpio.c +++ b/scripts/gen_init_cpio.c @@ -756,6 +756,7 @@ int main (int argc, char *argv[]) "ERROR: incorrect format, newline required line %d: '%s'\n", line_nr, line); ec = -1; + break; } for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {