From 1eb8d7ec2dff90e2efa5664d3b1703ed32749ae4 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Tue, 5 Jun 2018 12:11:48 +0200 Subject: lib/libnet/pxelinux: Make the size handling for pxelinux_load_cfg more logical The pxelinux_load_cfg() function always tried to load one byte less than its parameter said (so that we've got space for a terminating NUL-character later). This is not very intuitive, let's better ask for one byte less when we call the function. While we're at it, add a sanity check that the function really did not load more bytes than requested. Signed-off-by: Thomas Huth Reviewed-by: Greg Kurz Signed-off-by: Alexey Kardashevskiy --- lib/libnet/pxelinux.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/lib/libnet/pxelinux.c b/lib/libnet/pxelinux.c index 718ceca..939a92c 100644 --- a/lib/libnet/pxelinux.c +++ b/lib/libnet/pxelinux.c @@ -16,6 +16,7 @@ #include #include +#include #include "tftp.h" #include "pxelinux.h" @@ -95,7 +96,7 @@ static int pxelinux_load_cfg(filename_ip_t *fn_ip, uint8_t *mac, const char *uui return -1; } strcpy(baseptr, fn_ip->pl_cfgfile); - rc = pxelinux_tftp_load(fn_ip, cfgbuf, cfgbufsize - 1, retries); + rc = pxelinux_tftp_load(fn_ip, cfgbuf, cfgbufsize, retries); if (rc > 0) { return rc; } @@ -104,7 +105,7 @@ static int pxelinux_load_cfg(filename_ip_t *fn_ip, uint8_t *mac, const char *uui /* Try to load config file with name based on the VM UUID */ if (uuid) { strcpy(baseptr, uuid); - rc = pxelinux_tftp_load(fn_ip, cfgbuf, cfgbufsize - 1, retries); + rc = pxelinux_tftp_load(fn_ip, cfgbuf, cfgbufsize, retries); if (rc > 0) { return rc; } @@ -113,7 +114,7 @@ static int pxelinux_load_cfg(filename_ip_t *fn_ip, uint8_t *mac, const char *uui /* Look for config file with MAC address in its name */ sprintf(baseptr, "01-%02x-%02x-%02x-%02x-%02x-%02x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]); - rc = pxelinux_tftp_load(fn_ip, cfgbuf, cfgbufsize - 1, retries); + rc = pxelinux_tftp_load(fn_ip, cfgbuf, cfgbufsize, retries); if (rc > 0) { return rc; } @@ -127,7 +128,7 @@ static int pxelinux_load_cfg(filename_ip_t *fn_ip, uint8_t *mac, const char *uui fn_ip->own_ip & 0xff); for (idx = 0; idx <= 7; idx++) { baseptr[8 - idx] = 0; - rc = pxelinux_tftp_load(fn_ip, cfgbuf, cfgbufsize - 1, + rc = pxelinux_tftp_load(fn_ip, cfgbuf, cfgbufsize, retries); if (rc > 0) { return rc; @@ -137,7 +138,7 @@ static int pxelinux_load_cfg(filename_ip_t *fn_ip, uint8_t *mac, const char *uui /* Try "default" config file */ strcpy(baseptr, "default"); - rc = pxelinux_tftp_load(fn_ip, cfgbuf, cfgbufsize - 1, retries); + rc = pxelinux_tftp_load(fn_ip, cfgbuf, cfgbufsize, retries); return rc; } @@ -240,9 +241,10 @@ int pxelinux_load_parse_cfg(filename_ip_t *fn_ip, uint8_t *mac, const char *uuid { int rc; - rc = pxelinux_load_cfg(fn_ip, mac, uuid, retries, cfgbuf, cfgsize); + rc = pxelinux_load_cfg(fn_ip, mac, uuid, retries, cfgbuf, cfgsize - 1); if (rc < 0) return rc; + assert(rc < cfgsize); return pxelinux_parse_cfg(cfgbuf, rc, entries, max_entries, def_ent); } -- cgit v1.1