From: Dan Carpenter Date: Fri, 23 Apr 2021 11:48:31 +0000 (+0300) Subject: efi/libstub: prevent read overflow in find_file_option() X-Git-Tag: v5.10.79~3916 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=951f8ef71d691f754483cc9d871cb493379fdb35;p=platform%2Fkernel%2Flinux-rpi.git efi/libstub: prevent read overflow in find_file_option() [ Upstream commit c4039b29fe9637e1135912813f830994af4c867f ] If the buffer has slashes up to the end then this will read past the end of the array. I don't anticipate that this is an issue for many people in real life, but it's the right thing to do and it makes static checkers happy. Fixes: 7a88a6227dc7 ("efi/libstub: Fix path separator regression") Signed-off-by: Dan Carpenter Signed-off-by: Ard Biesheuvel Signed-off-by: Sasha Levin --- diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c index 4e81c60..dd95f33 100644 --- a/drivers/firmware/efi/libstub/file.c +++ b/drivers/firmware/efi/libstub/file.c @@ -103,7 +103,7 @@ static int find_file_option(const efi_char16_t *cmdline, int cmdline_len, return 0; /* Skip any leading slashes */ - while (cmdline[i] == L'/' || cmdline[i] == L'\\') + while (i < cmdline_len && (cmdline[i] == L'/' || cmdline[i] == L'\\')) i++; while (--result_len > 0 && i < cmdline_len) {