lockd: fix list corruption on lockd restart
[safe/jmp/linux-2.6] / fs / isofs / rock.c
index 9a81830..c2fb2dd 100644 (file)
@@ -127,6 +127,66 @@ out:
 }
 
 /*
+ * We think there's a record of type `sig' at rs->chr.  Parse the signature
+ * and make sure that there's really room for a record of that type.
+ */
+static int rock_check_overflow(struct rock_state *rs, int sig)
+{
+       int len;
+
+       switch (sig) {
+       case SIG('S', 'P'):
+               len = sizeof(struct SU_SP_s);
+               break;
+       case SIG('C', 'E'):
+               len = sizeof(struct SU_CE_s);
+               break;
+       case SIG('E', 'R'):
+               len = sizeof(struct SU_ER_s);
+               break;
+       case SIG('R', 'R'):
+               len = sizeof(struct RR_RR_s);
+               break;
+       case SIG('P', 'X'):
+               len = sizeof(struct RR_PX_s);
+               break;
+       case SIG('P', 'N'):
+               len = sizeof(struct RR_PN_s);
+               break;
+       case SIG('S', 'L'):
+               len = sizeof(struct RR_SL_s);
+               break;
+       case SIG('N', 'M'):
+               len = sizeof(struct RR_NM_s);
+               break;
+       case SIG('C', 'L'):
+               len = sizeof(struct RR_CL_s);
+               break;
+       case SIG('P', 'L'):
+               len = sizeof(struct RR_PL_s);
+               break;
+       case SIG('T', 'F'):
+               len = sizeof(struct RR_TF_s);
+               break;
+       case SIG('Z', 'F'):
+               len = sizeof(struct RR_ZF_s);
+               break;
+       default:
+               len = 0;
+               break;
+       }
+       len += offsetof(struct rock_ridge, u);
+       if (len > rs->len) {
+               printk(KERN_NOTICE "rock: directory entry would overflow "
+                               "storage\n");
+               printk(KERN_NOTICE "rock: sig=0x%02x, size=%d, remaining=%d\n",
+                               sig, len, rs->len);
+               return -EIO;
+       }
+       return 0;
+}
+
+/*
  * return length of name field; 0: not found, -1: to be ignored
  */
 int get_rock_ridge_filename(struct iso_directory_record *de,
@@ -149,13 +209,24 @@ repeat:
 
        while (rs.len > 2) { /* There may be one byte for padding somewhere */
                rr = (struct rock_ridge *)rs.chr;
+               /*
+                * Ignore rock ridge info if rr->len is out of range, but
+                * don't return -EIO because that would make the file
+                * invisible.
+                */
                if (rr->len < 3)
                        goto out;       /* Something got screwed up here */
                sig = isonum_721(rs.chr);
+               if (rock_check_overflow(&rs, sig))
+                       goto eio;
                rs.chr += rr->len;
                rs.len -= rr->len;
+               /*
+                * As above, just ignore the rock ridge info if rr->len
+                * is bogus.
+                */
                if (rs.len < 0)
-                       goto out;       /* corrupted isofs */
+                       goto out;       /* Something got screwed up here */
 
                switch (sig) {
                case SIG('R', 'R'):
@@ -213,6 +284,9 @@ repeat:
 out:
        kfree(rs.buffer);
        return ret;
+eio:
+       ret = -EIO;
+       goto out;
 }
 
 static int
@@ -242,13 +316,24 @@ parse_rock_ridge_inode_internal(struct iso_directory_record *de,
 repeat:
        while (rs.len > 2) { /* There may be one byte for padding somewhere */
                rr = (struct rock_ridge *)rs.chr;
+               /*
+                * Ignore rock ridge info if rr->len is out of range, but
+                * don't return -EIO because that would make the file
+                * invisible.
+                */
                if (rr->len < 3)
                        goto out;       /* Something got screwed up here */
                sig = isonum_721(rs.chr);
+               if (rock_check_overflow(&rs, sig))
+                       goto eio;
                rs.chr += rr->len;
                rs.len -= rr->len;
+               /*
+                * As above, just ignore the rock ridge info if rr->len
+                * is bogus.
+                */
                if (rs.len < 0)
-                       goto out;       /* corrupted isofs */
+                       goto out;       /* Something got screwed up here */
 
                switch (sig) {
 #ifndef CONFIG_ZISOFS          /* No flag for SF or ZF */
@@ -407,8 +492,10 @@ repeat:
                            isofs_iget(inode->i_sb,
                                       ISOFS_I(inode)->i_first_extent,
                                       0);
-                       if (!reloc)
+                       if (IS_ERR(reloc)) {
+                               ret = PTR_ERR(reloc);
                                goto out;
+                       }
                        inode->i_mode = reloc->i_mode;
                        inode->i_nlink = reloc->i_nlink;
                        inode->i_uid = reloc->i_uid;
@@ -479,6 +566,9 @@ repeat:
 out:
        kfree(rs.buffer);
        return ret;
+eio:
+       ret = -EIO;
+       goto out;
 }
 
 static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit)
@@ -618,6 +708,8 @@ repeat:
                if (rr->len < 3)
                        goto out;       /* Something got screwed up here */
                sig = isonum_721(rs.chr);
+               if (rock_check_overflow(&rs, sig))
+                       goto out;
                rs.chr += rr->len;
                rs.len -= rr->len;
                if (rs.len < 0)
@@ -682,6 +774,6 @@ error:
        return -EIO;
 }
 
-struct address_space_operations isofs_symlink_aops = {
+const struct address_space_operations isofs_symlink_aops = {
        .readpage = rock_ridge_symlink_readpage
 };