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mirror of git://sourceware.org/git/lvm2.git synced 2024-11-04 05:22:01 +03:00

libdm: fix segault for truncated string token.

This patch fixes problem reported here:

https://www.redhat.com/archives/dm-devel/2013-January/msg00311.html

Fixing it by separating function for duplicating string token.

---
When /etc/lvm/lvm.conf is truncated at the first '"' of a line, all LVM
utilities crash with a segfault.

The segfault only seems to occur if the last character is the first '"'
(double quote) of a line. If you truncate it at any other point, lvm
detects the error and report parse error

lvm.conf ends like this.

$hexdump -C lvm.conf
....
69 72 20 3d 20 22 2f 64  65 76 22 0a 0a 0a 20 20  |ir = "/dev"...  |
20 20 23 20 41 6e 20 61  72 72 61 79 20 6f 66 20  |  # An array of |
64 69 72 65 63 74 6f 72  69 65 73 20 74 68 61 74  |directories that|
20 63 6f 6e 74 61 69 6e  20 74 68 65 20 64 65 76  | contain the dev|
69 63 65 20 6e 6f 64 65  73 20 79 6f 75 20 77 69  |ice nodes you wi|
73 68 0a 20 20 20 20 23  20 74 6f 20 75 73 65 20  |sh.    # to use |
77 69 74 68 20 4c 56 4d  32 2e 0a 20 20 20 20 73  |with LVM2..    s|
63 61 6e 20 3d 20 5b 20  22 2f 78 22 2c 0a 20 20  |can = [ "/x",.  |
20 20 20 20 20 20 20 20  20 20 20 22              | "|
...

Reported-by: dongmao zhang <dmzhang suse com>
This commit is contained in:
Zdenek Kabelac 2013-02-01 11:07:44 +01:00
parent 9f433e6ee3
commit 4f439707fd
2 changed files with 25 additions and 6 deletions

View File

@ -1,5 +1,6 @@
Version 1.02.78 -
===================================
Fix segfault for truncated string token in config file after the first '"'.
Close open dmeventd FIFO file descriptors on exec (FD_CLOEXEC).
Fix resource leak in error path of dmeventd's umount of thin volume.
Automatically deactivate failed preloaded dm tree node.

View File

@ -360,6 +360,27 @@ int dm_config_write_node(const struct dm_config_node *cn, dm_putline_fn putline,
/*
* parser
*/
static char *_dup_string_tok(struct parser *p)
{
char *str;
p->tb++, p->te--; /* strip "'s */
if (p->te < p->tb) {
log_error("Parse error at byte %" PRIptrdiff_t " (line %d): "
"expected a string token.",
p->tb - p->fb + 1, p->line);
return NULL;
}
if (!(str = _dup_tok(p)))
return_NULL;
p->te++;
return str;
}
static struct dm_config_node *_file(struct parser *p)
{
struct dm_config_node *root = NULL, *n, *l = NULL;
@ -480,22 +501,19 @@ static struct dm_config_value *_type(struct parser *p)
case TOK_STRING:
v->type = DM_CFG_STRING;
p->tb++, p->te--; /* strip "'s */
if (!(v->v.str = _dup_tok(p)))
if (!(v->v.str = _dup_string_tok(p)))
return_NULL;
p->te++;
match(TOK_STRING);
break;
case TOK_STRING_ESCAPED:
v->type = DM_CFG_STRING;
p->tb++, p->te--; /* strip "'s */
if (!(str = _dup_tok(p)))
if (!(str = _dup_string_tok(p)))
return_NULL;
dm_unescape_double_quotes(str);
v->v.str = str;
p->te++;
match(TOK_STRING_ESCAPED);
break;