From 0e3f3f8a3d6e778eb3d8599475e6431ad6b51136 Mon Sep 17 00:00:00 2001 From: Steven Falco Date: Mon, 7 Oct 2013 09:51:48 -0400 Subject: [PATCH] Prevent null pointer dereference originating in cmd_pxe.c Pass a valid cmdtp into do_tftpb(), do_ext2load(), and do_get_fat(), to avoid possible crashes due to null pointer dereferencing. Commit d7884e047d08447dfd1374e9fa2fdf7ab36e56f5 does not go far enough. There is still at least one call chain that can result in a crash. The do_tftpb(), do_ext2load(), and do_get_fat() functions expect a valid cmdtp. Passing in NULL is particularly bad in the do_tftpb() case, because eventually boot_get_kernel() will be called with a NULL cmdtp: do_tftpb() -> netboot_common() -> bootm_maybe_autostart() -> do_bootm() -> do_bootm_states() -> bootm_find_os() -> boot_get_kernel() Around line 991 in cmd_bootm.c, boot_get_kernel() will dereference the null pointer, and the board will crash. Signed-off-by: Steven A. Falco --- common/cmd_pxe.c | 84 ++++++++++++++++++++++++------------------------ 1 file changed, 42 insertions(+), 42 deletions(-) diff --git a/common/cmd_pxe.c b/common/cmd_pxe.c index c5f4a221b8..79d3a061f5 100644 --- a/common/cmd_pxe.c +++ b/common/cmd_pxe.c @@ -114,16 +114,16 @@ static int get_bootfile_path(const char *file_path, char *bootfile_path, return 1; } -static int (*do_getfile)(const char *file_path, char *file_addr); +static int (*do_getfile)(cmd_tbl_t *cmdtp, const char *file_path, char *file_addr); -static int do_get_tftp(const char *file_path, char *file_addr) +static int do_get_tftp(cmd_tbl_t *cmdtp, const char *file_path, char *file_addr) { char *tftp_argv[] = {"tftp", NULL, NULL, NULL}; tftp_argv[1] = file_addr; tftp_argv[2] = (void *)file_path; - if (do_tftpb(NULL, 0, 3, tftp_argv)) + if (do_tftpb(cmdtp, 0, 3, tftp_argv)) return -ENOENT; return 1; @@ -131,27 +131,27 @@ static int do_get_tftp(const char *file_path, char *file_addr) static char *fs_argv[5]; -static int do_get_ext2(const char *file_path, char *file_addr) +static int do_get_ext2(cmd_tbl_t *cmdtp, const char *file_path, char *file_addr) { #ifdef CONFIG_CMD_EXT2 fs_argv[0] = "ext2load"; fs_argv[3] = file_addr; fs_argv[4] = (void *)file_path; - if (!do_ext2load(NULL, 0, 5, fs_argv)) + if (!do_ext2load(cmdtp, 0, 5, fs_argv)) return 1; #endif return -ENOENT; } -static int do_get_fat(const char *file_path, char *file_addr) +static int do_get_fat(cmd_tbl_t *cmdtp, const char *file_path, char *file_addr) { #ifdef CONFIG_CMD_FAT fs_argv[0] = "fatload"; fs_argv[3] = file_addr; fs_argv[4] = (void *)file_path; - if (!do_fat_fsload(NULL, 0, 5, fs_argv)) + if (!do_fat_fsload(cmdtp, 0, 5, fs_argv)) return 1; #endif return -ENOENT; @@ -165,7 +165,7 @@ static int do_get_fat(const char *file_path, char *file_addr) * * Returns 1 for success, or < 0 on error. */ -static int get_relfile(const char *file_path, void *file_addr) +static int get_relfile(cmd_tbl_t *cmdtp, const char *file_path, void *file_addr) { size_t path_len; char relfile[MAX_TFTP_PATH_LEN+1]; @@ -194,7 +194,7 @@ static int get_relfile(const char *file_path, void *file_addr) sprintf(addr_buf, "%p", file_addr); - return do_getfile(relfile, addr_buf); + return do_getfile(cmdtp, relfile, addr_buf); } /* @@ -204,13 +204,13 @@ static int get_relfile(const char *file_path, void *file_addr) * * Returns 1 on success, or < 0 for error. */ -static int get_pxe_file(const char *file_path, void *file_addr) +static int get_pxe_file(cmd_tbl_t *cmdtp, const char *file_path, void *file_addr) { unsigned long config_file_size; char *tftp_filesize; int err; - err = get_relfile(file_path, file_addr); + err = get_relfile(cmdtp, file_path, file_addr); if (err < 0) return err; @@ -241,7 +241,7 @@ static int get_pxe_file(const char *file_path, void *file_addr) * * Returns 1 on success or < 0 on error. */ -static int get_pxelinux_path(const char *file, void *pxefile_addr_r) +static int get_pxelinux_path(cmd_tbl_t *cmdtp, const char *file, void *pxefile_addr_r) { size_t base_len = strlen(PXELINUX_DIR); char path[MAX_TFTP_PATH_LEN+1]; @@ -254,7 +254,7 @@ static int get_pxelinux_path(const char *file, void *pxefile_addr_r) sprintf(path, PXELINUX_DIR "%s", file); - return get_pxe_file(path, pxefile_addr_r); + return get_pxe_file(cmdtp, path, pxefile_addr_r); } /* @@ -262,7 +262,7 @@ static int get_pxelinux_path(const char *file, void *pxefile_addr_r) * * Returns 1 on success or < 0 on error. */ -static int pxe_uuid_path(void *pxefile_addr_r) +static int pxe_uuid_path(cmd_tbl_t *cmdtp, void *pxefile_addr_r) { char *uuid_str; @@ -271,7 +271,7 @@ static int pxe_uuid_path(void *pxefile_addr_r) if (!uuid_str) return -ENOENT; - return get_pxelinux_path(uuid_str, pxefile_addr_r); + return get_pxelinux_path(cmdtp, uuid_str, pxefile_addr_r); } /* @@ -280,7 +280,7 @@ static int pxe_uuid_path(void *pxefile_addr_r) * * Returns 1 on success or < 0 on error. */ -static int pxe_mac_path(void *pxefile_addr_r) +static int pxe_mac_path(cmd_tbl_t *cmdtp, void *pxefile_addr_r) { char mac_str[21]; int err; @@ -290,7 +290,7 @@ static int pxe_mac_path(void *pxefile_addr_r) if (err < 0) return err; - return get_pxelinux_path(mac_str, pxefile_addr_r); + return get_pxelinux_path(cmdtp, mac_str, pxefile_addr_r); } /* @@ -300,7 +300,7 @@ static int pxe_mac_path(void *pxefile_addr_r) * * Returns 1 on success or < 0 on error. */ -static int pxe_ipaddr_paths(void *pxefile_addr_r) +static int pxe_ipaddr_paths(cmd_tbl_t *cmdtp, void *pxefile_addr_r) { char ip_addr[9]; int mask_pos, err; @@ -308,7 +308,7 @@ static int pxe_ipaddr_paths(void *pxefile_addr_r) sprintf(ip_addr, "%08X", ntohl(NetOurIP)); for (mask_pos = 7; mask_pos >= 0; mask_pos--) { - err = get_pxelinux_path(ip_addr, pxefile_addr_r); + err = get_pxelinux_path(cmdtp, ip_addr, pxefile_addr_r); if (err > 0) return err; @@ -359,16 +359,16 @@ do_pxe_get(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) * Keep trying paths until we successfully get a file we're looking * for. */ - if (pxe_uuid_path((void *)pxefile_addr_r) > 0 || - pxe_mac_path((void *)pxefile_addr_r) > 0 || - pxe_ipaddr_paths((void *)pxefile_addr_r) > 0) { + if (pxe_uuid_path(cmdtp, (void *)pxefile_addr_r) > 0 || + pxe_mac_path(cmdtp, (void *)pxefile_addr_r) > 0 || + pxe_ipaddr_paths(cmdtp, (void *)pxefile_addr_r) > 0) { printf("Config file found\n"); return 0; } while (pxe_default_paths[i]) { - if (get_pxelinux_path(pxe_default_paths[i], + if (get_pxelinux_path(cmdtp, pxe_default_paths[i], (void *)pxefile_addr_r) > 0) { printf("Config file found\n"); return 0; @@ -388,7 +388,7 @@ do_pxe_get(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) * * Returns 1 on success or < 0 on error. */ -static int get_relfile_envaddr(const char *file_path, const char *envaddr_name) +static int get_relfile_envaddr(cmd_tbl_t *cmdtp, const char *file_path, const char *envaddr_name) { unsigned long file_addr; char *envaddr; @@ -401,7 +401,7 @@ static int get_relfile_envaddr(const char *file_path, const char *envaddr_name) if (strict_strtoul(envaddr, 16, &file_addr) < 0) return -EINVAL; - return get_relfile(file_path, (void *)file_addr); + return get_relfile(cmdtp, file_path, (void *)file_addr); } /* @@ -599,7 +599,7 @@ static int label_boot(cmd_tbl_t *cmdtp, struct pxe_label *label) } if (label->initrd) { - if (get_relfile_envaddr(label->initrd, "ramdisk_addr_r") < 0) { + if (get_relfile_envaddr(cmdtp, label->initrd, "ramdisk_addr_r") < 0) { printf("Skipping %s for failure retrieving initrd\n", label->name); return 1; @@ -613,7 +613,7 @@ static int label_boot(cmd_tbl_t *cmdtp, struct pxe_label *label) bootm_argv[2] = "-"; } - if (get_relfile_envaddr(label->kernel, "kernel_addr_r") < 0) { + if (get_relfile_envaddr(cmdtp, label->kernel, "kernel_addr_r") < 0) { printf("Skipping %s for failure retrieving kernel\n", label->name); return 1; @@ -673,7 +673,7 @@ static int label_boot(cmd_tbl_t *cmdtp, struct pxe_label *label) /* if fdt label is defined then get fdt from server */ if (bootm_argv[3] && label->fdt) { - if (get_relfile_envaddr(label->fdt, "fdt_addr_r") < 0) { + if (get_relfile_envaddr(cmdtp, label->fdt, "fdt_addr_r") < 0) { printf("Skipping %s for failure retrieving fdt\n", label->name); return 1; @@ -950,7 +950,7 @@ static int parse_integer(char **c, int *dst) return 1; } -static int parse_pxefile_top(char *p, struct pxe_menu *cfg, int nest_level); +static int parse_pxefile_top(cmd_tbl_t *cmdtp, char *p, struct pxe_menu *cfg, int nest_level); /* * Parse an include statement, and retrieve and parse the file it mentions. @@ -960,7 +960,7 @@ static int parse_pxefile_top(char *p, struct pxe_menu *cfg, int nest_level); * include, nest_level has already been incremented and doesn't need to be * incremented here. */ -static int handle_include(char **c, char *base, +static int handle_include(cmd_tbl_t *cmdtp, char **c, char *base, struct pxe_menu *cfg, int nest_level) { char *include_path; @@ -975,14 +975,14 @@ static int handle_include(char **c, char *base, return err; } - err = get_pxe_file(include_path, base); + err = get_pxe_file(cmdtp, include_path, base); if (err < 0) { printf("Couldn't retrieve %s\n", include_path); return err; } - return parse_pxefile_top(base, cfg, nest_level); + return parse_pxefile_top(cmdtp, base, cfg, nest_level); } /* @@ -995,7 +995,7 @@ static int handle_include(char **c, char *base, * nest_level should be 1 when parsing the top level pxe file, 2 when parsing * a file it includes, 3 when parsing a file included by that file, and so on. */ -static int parse_menu(char **c, struct pxe_menu *cfg, char *b, int nest_level) +static int parse_menu(cmd_tbl_t *cmdtp, char **c, struct pxe_menu *cfg, char *b, int nest_level) { struct token t; char *s = *c; @@ -1010,7 +1010,7 @@ static int parse_menu(char **c, struct pxe_menu *cfg, char *b, int nest_level) break; case T_INCLUDE: - err = handle_include(c, b + strlen(b) + 1, cfg, + err = handle_include(cmdtp, c, b + strlen(b) + 1, cfg, nest_level + 1); break; @@ -1172,7 +1172,7 @@ static int parse_label(char **c, struct pxe_menu *cfg) * * Returns 1 on success, < 0 on error. */ -static int parse_pxefile_top(char *p, struct pxe_menu *cfg, int nest_level) +static int parse_pxefile_top(cmd_tbl_t *cmdtp, char *p, struct pxe_menu *cfg, int nest_level) { struct token t; char *s, *b, *label_name; @@ -1194,7 +1194,7 @@ static int parse_pxefile_top(char *p, struct pxe_menu *cfg, int nest_level) switch (t.type) { case T_MENU: cfg->prompt = 1; - err = parse_menu(&p, cfg, b, nest_level); + err = parse_menu(cmdtp, &p, cfg, b, nest_level); break; case T_TIMEOUT: @@ -1219,7 +1219,7 @@ static int parse_pxefile_top(char *p, struct pxe_menu *cfg, int nest_level) break; case T_INCLUDE: - err = handle_include(&p, b + ALIGN(strlen(b), 4), cfg, + err = handle_include(cmdtp, &p, b + ALIGN(strlen(b), 4), cfg, nest_level + 1); break; @@ -1276,7 +1276,7 @@ static void destroy_pxe_menu(struct pxe_menu *cfg) * files it includes). The resulting pxe_menu struct can be free()'d by using * the destroy_pxe_menu() function. */ -static struct pxe_menu *parse_pxefile(char *menucfg) +static struct pxe_menu *parse_pxefile(cmd_tbl_t *cmdtp, char *menucfg) { struct pxe_menu *cfg; @@ -1289,7 +1289,7 @@ static struct pxe_menu *parse_pxefile(char *menucfg) INIT_LIST_HEAD(&cfg->labels); - if (parse_pxefile_top(menucfg, cfg, 1) < 0) { + if (parse_pxefile_top(cmdtp, menucfg, cfg, 1) < 0) { destroy_pxe_menu(cfg); return NULL; } @@ -1446,7 +1446,7 @@ do_pxe_boot(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) return 1; } - cfg = parse_pxefile((char *)(pxefile_addr_r)); + cfg = parse_pxefile(cmdtp, (char *)(pxefile_addr_r)); if (cfg == NULL) { printf("Error parsing config file\n"); @@ -1544,12 +1544,12 @@ int do_sysboot(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) return 1; } - if (get_pxe_file(filename, (void *)pxefile_addr_r) < 0) { + if (get_pxe_file(cmdtp, filename, (void *)pxefile_addr_r) < 0) { printf("Error reading config file\n"); return 1; } - cfg = parse_pxefile((char *)(pxefile_addr_r)); + cfg = parse_pxefile(cmdtp, (char *)(pxefile_addr_r)); if (cfg == NULL) { printf("Error parsing config file\n"); -- 2.25.1