From: Ard Biesheuvel Date: Wed, 1 Sep 2021 06:33:19 +0000 (+0200) Subject: efi/cper: use stack buffer for error record decoding X-Git-Tag: v4.19.213~34 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=6dca770d20f0e6ff4ede64211696b3553ec5d163;p=users%2Fdwmw2%2Flinux.git efi/cper: use stack buffer for error record decoding commit b3a72ca80351917cc23f9e24c35f3c3979d3c121 upstream. Joe reports that using a statically allocated buffer for converting CPER error records into human readable text is probably a bad idea. Even though we are not aware of any actual issues, a stack buffer is clearly a better choice here anyway, so let's move the buffer into the stack frames of the two functions that refer to it. Cc: Reported-by: Joe Perches Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c index 97da083afd324..aa4abf1a94a13 100644 --- a/drivers/firmware/efi/cper.c +++ b/drivers/firmware/efi/cper.c @@ -37,8 +37,6 @@ #include #include -static char rcd_decode_str[CPER_REC_LEN]; - /* * CPER record ID need to be unique even after reboot, because record * ID is used as index for ERST storage, while CPER records from @@ -311,6 +309,7 @@ const char *cper_mem_err_unpack(struct trace_seq *p, struct cper_mem_err_compact *cmem) { const char *ret = trace_seq_buffer_ptr(p); + char rcd_decode_str[CPER_REC_LEN]; if (cper_mem_err_location(cmem, rcd_decode_str)) trace_seq_printf(p, "%s", rcd_decode_str); @@ -325,6 +324,7 @@ static void cper_print_mem(const char *pfx, const struct cper_sec_mem_err *mem, int len) { struct cper_mem_err_compact cmem; + char rcd_decode_str[CPER_REC_LEN]; /* Don't trust UEFI 2.1/2.2 structure with bad validation bits */ if (len == sizeof(struct cper_sec_mem_err_old) &&