Date: Mon, 16 Oct 2023 23:32:18 GMT From: John Baldwin <jhb@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: ae2fc74fe76c - main - bsdinstall partedit: Avoid potential buffer overflow in newfs_command Message-ID: <202310162332.39GNWIZR094645@gitrepo.freebsd.org>
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The branch main has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=ae2fc74fe76ca8b89c5ef0081ef3f4008f83de41 commit ae2fc74fe76ca8b89c5ef0081ef3f4008f83de41 Author: John Baldwin <jhb@FreeBSD.org> AuthorDate: 2023-10-16 23:25:03 +0000 Commit: John Baldwin <jhb@FreeBSD.org> CommitDate: 2023-10-16 23:25:03 +0000 bsdinstall partedit: Avoid potential buffer overflow in newfs_command Allocate the buffer holding the newfs command string dynamically (building the string via open_memstream) rather than storing the command into a caller-supplied buffer of unknown length. Reviewed by: emaste Differential Revision: https://reviews.freebsd.org/D42237 --- usr.sbin/bsdinstall/partedit/gpart_ops.c | 68 +++++++++++++++++++------------- 1 file changed, 40 insertions(+), 28 deletions(-) diff --git a/usr.sbin/bsdinstall/partedit/gpart_ops.c b/usr.sbin/bsdinstall/partedit/gpart_ops.c index b1d4d0f23315..7f34819a3d4d 100644 --- a/usr.sbin/bsdinstall/partedit/gpart_ops.c +++ b/usr.sbin/bsdinstall/partedit/gpart_ops.c @@ -86,12 +86,16 @@ scheme_supports_labels(const char *scheme) return (0); } -static void -newfs_command(const char *fstype, char *command, int use_default) +static char * +newfs_command(const char *fstype, int use_default) { struct bsddialog_conf conf; + FILE *fp; + char *buf; + size_t len; bsddialog_initconf(&conf); + fp = open_memstream(&buf, &len); if (strcmp(fstype, "freebsd-ufs") == 0) { int i; @@ -115,21 +119,21 @@ newfs_command(const char *fstype, char *command, int use_default) choice = bsddialog_checklist(&conf, "", 0, 0, 0, nitems(items), items, NULL); if (choice == BSDDIALOG_CANCEL) - return; + goto out; } - strcpy(command, "newfs "); + fputs("newfs ", fp); for (i = 0; i < (int)nitems(items); i++) { if (items[i].on == false) continue; if (strcmp(items[i].name, "UFS1") == 0) - strcat(command, "-O1 "); + fputs("-O1 ", fp); else if (strcmp(items[i].name, "SU") == 0) - strcat(command, "-U "); + fputs("-U ", fp); else if (strcmp(items[i].name, "SUJ") == 0) - strcat(command, "-j "); + fputs("-j ", fp); else if (strcmp(items[i].name, "TRIM") == 0) - strcat(command, "-t "); + fputs("-t ", fp); } } else if (strcmp(fstype, "freebsd-zfs") == 0) { int i; @@ -153,30 +157,31 @@ newfs_command(const char *fstype, char *command, int use_default) choice = bsddialog_checklist(&conf, "", 0, 0, 0, nitems(items), items, NULL); if (choice == BSDDIALOG_CANCEL) - return; + goto out; } - strcpy(command, "zpool create -f -m none "); + fputs("zpool create -f -m none ", fp); if (getenv("BSDINSTALL_TMPBOOT") != NULL) { char zfsboot_path[MAXPATHLEN]; + snprintf(zfsboot_path, sizeof(zfsboot_path), "%s/zfs", getenv("BSDINSTALL_TMPBOOT")); mkdir(zfsboot_path, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH); - sprintf(command, "%s -o cachefile=%s/zpool.cache ", - command, zfsboot_path); + fprintf(fp, " -o cachefile=%s/zpool.cache ", + zfsboot_path); } for (i = 0; i < (int)nitems(items); i++) { if (items[i].on == false) continue; if (strcmp(items[i].name, "fletcher4") == 0) - strcat(command, "-O checksum=fletcher4 "); + fputs("-O checksum=fletcher4 ", fp); else if (strcmp(items[i].name, "fletcher2") == 0) - strcat(command, "-O checksum=fletcher2 "); + fputs("-O checksum=fletcher2 ", fp); else if (strcmp(items[i].name, "sha256") == 0) - strcat(command, "-O checksum=sha256 "); + fputs("-O checksum=sha256 ", fp); else if (strcmp(items[i].name, "atime") == 0) - strcat(command, "-O atime=off "); + fputs("-O atime=off ", fp); } } else if (strcmp(fstype, "fat32") == 0 || strcmp(fstype, "efi") == 0 || strcmp(fstype, "ms-basic-data") == 0) { @@ -196,19 +201,19 @@ newfs_command(const char *fstype, char *command, int use_default) choice = bsddialog_radiolist(&conf, "", 0, 0, 0, nitems(items), items, NULL); if (choice == BSDDIALOG_CANCEL) - return; + goto out; } - strcpy(command, "newfs_msdos "); + fputs("newfs_msdos ", fp); for (i = 0; i < (int)nitems(items); i++) { if (items[i].on == false) continue; if (strcmp(items[i].name, "FAT32") == 0) - strcat(command, "-F 32 -c 1"); + fputs("-F 32 -c 1", fp); else if (strcmp(items[i].name, "FAT16") == 0) - strcat(command, "-F 16 "); + fputs("-F 16 ", fp); else if (strcmp(items[i].name, "FAT12") == 0) - strcat(command, "-F 12 "); + fputs("-F 12 ", fp); } } else { if (!use_default) { @@ -216,8 +221,11 @@ newfs_command(const char *fstype, char *command, int use_default) bsddialog_msgbox(&conf, "No configurable options exist " "for this filesystem.", 0, 0); } - command[0] = '\0'; } + +out: + fclose(fp); + return (buf); } const char * @@ -539,7 +547,7 @@ gpart_edit(struct gprovider *pp) const char *errstr, *oldtype, *scheme; struct partition_metadata *md; char sizestr[32]; - char newfs[255]; + char *newfs; intmax_t idx; int hadlabel, choice, nitems; unsigned i; @@ -687,10 +695,11 @@ editpart: } gctl_free(r); - newfs_command(items[0].value, newfs, 1); + newfs = newfs_command(items[0].value, 1); set_default_part_metadata(pp->lg_name, scheme, items[0].value, items[2].value, (strcmp(oldtype, items[0].value) != 0) ? newfs : NULL); + free(newfs); endedit: if (strcmp(oldtype, items[0].value) != 0 && cp != NULL) @@ -1022,7 +1031,7 @@ gpart_create(struct gprovider *pp, const char *default_type, struct ggeom *geom; const char *errstr, *scheme; char sizestr[32], startstr[32], output[64], *newpartname; - char newfs[255], options_fstype[64]; + char *newfs, options_fstype[64]; intmax_t maxsize, size, sector, firstfree, stripe; uint64_t bytes; int nitems, choice, junk; @@ -1123,7 +1132,7 @@ gpart_create(struct gprovider *pp, const char *default_type, /* Default options */ strncpy(options_fstype, items[0].init, sizeof(options_fstype)); - newfs_command(options_fstype, newfs, 1); + newfs = newfs_command(options_fstype, 1); init_allocated = false; addpartform: @@ -1142,9 +1151,10 @@ addpartform: case BSDDIALOG_CANCEL: return; case BSDDIALOG_EXTRA: /* Options */ + free(newfs); strncpy(options_fstype, items[0].value, sizeof(options_fstype)); - newfs_command(options_fstype, newfs, 0); + newfs = newfs_command(options_fstype, 0); for (i = 0; i < nitems(items); i++) { if (init_allocated) free((char*)items[i].init); @@ -1166,8 +1176,9 @@ addpartform: * their choices in favor of the new filesystem's defaults. */ if (strcmp(options_fstype, items[0].value) != 0) { + free(newfs); strncpy(options_fstype, items[0].value, sizeof(options_fstype)); - newfs_command(options_fstype, newfs, 1); + newfs = newfs_command(options_fstype, 1); } size = maxsize; @@ -1319,6 +1330,7 @@ addpartform: else set_default_part_metadata(newpartname, scheme, items[0].value, items[2].value, newfs); + free(newfs); for (i = 0; i < nitems(items); i++) { if (items[i].value != NULL) {
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