From 3e4414508b409a21b023b9ca4532f62003e0db97 Mon Sep 17 00:00:00 2001 From: "arun@codemovers.org" Date: Fri, 10 Sep 2004 20:54:04 -0700 Subject: [PATCH] [PATCH] udev - read long lines from config files overflow fix Hi Kay, On 23:12 Sat 04 Sep , Kay Sievers wrote: > Cool, a real bug :) > Thanks, for the patch. I think it would be better to skip lenghth exceeding > lines instead of cutting it and continue. While looking at it I restructured > the buffer reading logic a bit and fixed another stupid bug. Thanks for the cleanup. You may have overlooked the fix for udev_config.c(parsing udev.conf) in your patch. So, I've adapted the fixes you applied to namedev_parse.c to this file also. Also, while 'eating' the whitespace the 'count' doesn't get decremented. This leads strncpy to copy the number of whitespace minus 1 characters from the next line. Minus 1 because it copies '\n' from the current line. while (isspace(bufline[0])) { bufline++; + count--; } . . . strncpy(line, bufline, count); Included patch(against udev-030) contains the above fixes as well as your fixes. Signed-off-by: Arun Bhanu --- klibc_fixups.c | 17 +++---- namedev_parse.c | 118 ++++++++++++++++++++++++++++++------------------ udev.h | 2 + udev_config.c | 40 +++++++++------- 4 files changed, 109 insertions(+), 68 deletions(-) diff --git a/klibc_fixups.c b/klibc_fixups.c index bbacfbdc..d1a452a4 100644 --- a/klibc_fixups.c +++ b/klibc_fixups.c @@ -41,8 +41,9 @@ static unsigned long get_id_by_name(const char *uname, const char *dbfile) { unsigned long id = -1; - char line[255]; + char line[LINE_SIZE]; char *buf; + char *bufline; size_t bufsize; size_t cur; size_t count; @@ -59,19 +60,19 @@ static unsigned long get_id_by_name(const char *uname, const char *dbfile) } /* loop through the whole file */ - cur = 0; - while (1) { + while (cur < bufsize) { count = buf_get_line(buf, bufsize, cur); + bufline = &buf[cur]; + cur += count+1; + + if (count >= LINE_SIZE) + continue; - strncpy(line, buf + cur, count); + strncpy(line, bufline, count); line[count] = '\0'; pos = line; - cur += count+1; - if (cur > bufsize) - break; - /* get name */ name = strsep(&pos, ":"); if (name == NULL) diff --git a/namedev_parse.c b/namedev_parse.c index 679efae1..4bb1a97c 100644 --- a/namedev_parse.c +++ b/namedev_parse.c @@ -58,7 +58,7 @@ void dump_config_dev(struct config_device *dev) { dbg_parse("name='%s', symlink='%s', bus='%s', place='%s', id='%s', " "sysfs_file[0]='%s', sysfs_value[0]='%s', " - "kernel='%s', program='%s', result='%s'", + "kernel='%s', program='%s', result='%s'" "owner='%s', group='%s', mode=%#o", dev->name, dev->symlink, dev->bus, dev->place, dev->id, dev->sysfs_pair[0].file, dev->sysfs_pair[0].value, @@ -144,7 +144,8 @@ static char *get_key_attribute(char *str) static int namedev_parse_rules(char *filename) { - char line[255]; + char line[LINE_SIZE]; + char *bufline; int lineno; char *temp; char *temp2; @@ -155,6 +156,7 @@ static int namedev_parse_rules(char *filename) size_t cur; size_t count; int program_given = 0; + int valid; int retval = 0; struct config_device dev; @@ -168,35 +170,41 @@ static int namedev_parse_rules(char *filename) /* loop through the whole file */ cur = 0; lineno = 0; - while (1) { + while (cur < bufsize) { count = buf_get_line(buf, bufsize, cur); - - strncpy(line, buf + cur, count); - line[count] = '\0'; - temp = line; - lineno++; - + bufline = &buf[cur]; cur += count+1; - if (cur > bufsize) - break; - - dbg_parse("read '%s'", temp); + lineno++; - /* eat the whitespace */ - while (isspace(*temp)) - ++temp; + if (count >= LINE_SIZE) { + info("line too long, rule skipped %s, line %d", + filename, lineno); + continue; + } /* empty line? */ - if ((*temp == '\0') || (*temp == '\n')) + if (bufline[0] == '\0' || bufline[0] == '\n') continue; + /* eat the whitespace */ + while (isspace(bufline[0])) { + bufline++; + count--; + } + /* see if this is a comment */ - if (*temp == COMMENT_CHARACTER) + if (bufline[0] == COMMENT_CHARACTER) continue; - memset(&dev, 0x00, sizeof(struct config_device)); + strncpy(line, bufline, count); + line[count] = '\0'; + dbg_parse("read '%s'", line); /* get all known keys */ + memset(&dev, 0x00, sizeof(struct config_device)); + temp = line; + valid = 0; + while (1) { retval = parse_get_pair(&temp, &temp2, &temp3); if (retval) @@ -204,16 +212,19 @@ static int namedev_parse_rules(char *filename) if (strcasecmp(temp2, FIELD_BUS) == 0) { strfieldcpy(dev.bus, temp3); + valid = 1; continue; } if (strcasecmp(temp2, FIELD_ID) == 0) { strfieldcpy(dev.id, temp3); + valid = 1; continue; } if (strcasecmp(temp2, FIELD_PLACE) == 0) { strfieldcpy(dev.place, temp3); + valid = 1; continue; } @@ -238,54 +249,62 @@ static int namedev_parse_rules(char *filename) } strfieldcpy(pair->file, attr); strfieldcpy(pair->value, temp3); + valid = 1; } continue; } if (strcasecmp(temp2, FIELD_KERNEL) == 0) { strfieldcpy(dev.kernel, temp3); + valid = 1; continue; } if (strcasecmp(temp2, FIELD_PROGRAM) == 0) { program_given = 1; strfieldcpy(dev.program, temp3); + valid = 1; continue; } if (strcasecmp(temp2, FIELD_RESULT) == 0) { strfieldcpy(dev.result, temp3); + valid = 1; continue; } if (strncasecmp(temp2, FIELD_NAME, sizeof(FIELD_NAME)-1) == 0) { attr = get_key_attribute(temp2 + sizeof(FIELD_NAME)-1); - if (attr != NULL) - if (strcasecmp(attr, ATTR_PARTITIONS) == 0) { + if (attr != NULL && strcasecmp(attr, ATTR_PARTITIONS) == 0) { dbg_parse("creation of partition nodes requested"); dev.partitions = PARTITIONS_COUNT; } strfieldcpy(dev.name, temp3); + valid = 1; continue; } if (strcasecmp(temp2, FIELD_SYMLINK) == 0) { strfieldcpy(dev.symlink, temp3); + valid = 1; continue; } if (strcasecmp(temp2, FIELD_OWNER) == 0) { strfieldcpy(dev.owner, temp3); + valid = 1; continue; } if (strcasecmp(temp2, FIELD_GROUP) == 0) { strfieldcpy(dev.group, temp3); + valid = 1; continue; } if (strcasecmp(temp2, FIELD_MODE) == 0) { dev.mode = strtol(temp3, NULL, 8); + valid = 1; continue; } @@ -293,16 +312,20 @@ static int namedev_parse_rules(char *filename) goto error; } + /* skip line if not any valid key was found */ + if (!valid) + goto error; + /* simple plausibility checks for given keys */ if ((dev.sysfs_pair[0].file[0] == '\0') ^ (dev.sysfs_pair[0].value[0] == '\0')) { - dbg("inconsistency in " FIELD_SYSFS " key"); + info("inconsistency in " FIELD_SYSFS " key"); goto error; } if ((dev.result[0] != '\0') && (program_given == 0)) { - dbg(FIELD_RESULT " is only useful when " - FIELD_PROGRAM " is called in any rule before"); + info(FIELD_RESULT " is only useful when " + FIELD_PROGRAM " is called in any rule before"); goto error; } @@ -313,8 +336,8 @@ static int namedev_parse_rules(char *filename) dbg("add_config_dev returned with error %d", retval); continue; error: - dbg("%s:%d:%d: parse error, rule skipped", - filename, lineno, temp - line); + info("parse error %s, line %d:%d, rule skipped", + filename, lineno, temp - line); } } @@ -324,7 +347,8 @@ error: static int namedev_parse_permissions(char *filename) { - char line[255]; + char line[LINE_SIZE]; + char *bufline; char *temp; char *temp2; char *buf; @@ -333,6 +357,7 @@ static int namedev_parse_permissions(char *filename) size_t count; int retval = 0; struct perm_device dev; + int lineno; if (file_map(filename, &buf, &bufsize) == 0) { dbg("reading '%s' as permissions file", filename); @@ -343,34 +368,41 @@ static int namedev_parse_permissions(char *filename) /* loop through the whole file */ cur = 0; - while (1) { + lineno = 0; + while (cur < bufsize) { count = buf_get_line(buf, bufsize, cur); - - strncpy(line, buf + cur, count); - line[count] = '\0'; - temp = line; - + bufline = &buf[cur]; cur += count+1; - if (cur > bufsize) - break; - - dbg_parse("read '%s'", temp); + lineno++; - /* eat the whitespace at the beginning of the line */ - while (isspace(*temp)) - ++temp; + if (count >= LINE_SIZE) { + info("line too long, rule skipped %s, line %d", + filename, lineno); + continue; + } /* empty line? */ - if ((*temp == '\0') || (*temp == '\n')) + if (bufline[0] == '\0' || bufline[0] == '\n') continue; + /* eat the whitespace */ + while (isspace(bufline[0])) { + bufline++; + count--; + } + /* see if this is a comment */ - if (*temp == COMMENT_CHARACTER) + if (bufline[0] == COMMENT_CHARACTER) continue; - memset(&dev, 0x00, sizeof(dev)); + strncpy(line, bufline, count); + line[count] = '\0'; + dbg_parse("read '%s'", line); /* parse the line */ + memset(&dev, 0x00, sizeof(struct perm_device)); + temp = line; + temp2 = strsep(&temp, ":"); if (!temp2) { dbg("cannot parse line '%s'", line); diff --git a/udev.h b/udev.h index 717c1218..7c5d18a3 100644 --- a/udev.h +++ b/udev.h @@ -38,6 +38,8 @@ #define SUBSYSTEM_SIZE 32 #define SEQNUM_SIZE 32 +#define LINE_SIZE 256 + /* length of public data */ #define UDEVICE_LEN (offsetof(struct udevice, bus_id)) diff --git a/udev_config.c b/udev_config.c index 19f690c7..20b6c75d 100644 --- a/udev_config.c +++ b/udev_config.c @@ -127,7 +127,8 @@ int parse_get_pair(char **orig_string, char **left, char **right) static int parse_config_file(void) { - char line[255]; + char line[LINE_SIZE]; + char *bufline; char *temp; char *variable; char *value; @@ -148,32 +149,37 @@ static int parse_config_file(void) /* loop through the whole file */ lineno = 0; cur = 0; - while (1) { + while (cur < bufsize) { count = buf_get_line(buf, bufsize, cur); - - strncpy(line, buf + cur, count); - line[count] = '\0'; - temp = line; - lineno++; - + bufline = &buf[cur]; cur += count+1; - if (cur > bufsize) - break; - - dbg_parse("read '%s'", temp); + lineno++; - /* eat the whitespace at the beginning of the line */ - while (isspace(*temp)) - ++temp; + if (count >= LINE_SIZE) { + info("line too long, conf line skipped %s, line %d", + udev_config_filename, lineno); + continue; + } /* empty line? */ - if (*temp == 0x00) + if (bufline[0] == '\0' || bufline[0] == '\n') continue; + /* eat the whitespace */ + while (isspace(bufline[0])) { + bufline++; + count--; + } + /* see if this is a comment */ - if (*temp == COMMENT_CHARACTER) + if (bufline[0] == COMMENT_CHARACTER) continue; + strncpy(line, bufline, count); + line[count] = '\0'; + temp = line; + dbg_parse("read '%s'", temp); + retval = parse_get_pair(&temp, &variable, &value); if (retval != 0) info("%s:%d:%Zd: error parsing '%s'", -- 2.39.5