diff options
| -rw-r--r-- | fs/udf/super.c | 67 |
1 files changed, 43 insertions, 24 deletions
diff --git a/fs/udf/super.c b/fs/udf/super.c index 36661ac..5e2c8c8 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -78,6 +78,15 @@ #define VSD_FIRST_SECTOR_OFFSET 32768 #define VSD_MAX_SECTOR_OFFSET 0x800000 +/* + * Maximum number of Terminating Descriptor / Logical Volume Integrity + * Descriptor redirections. The chosen numbers are arbitrary - just that we + * hopefully don't limit any real use of rewritten inode on write-once media + * but avoid looping for too long on corrupted media. + */ +#define UDF_MAX_TD_NESTING 64 +#define UDF_MAX_LVID_NESTING 1000 + enum { UDF_MAX_LINKS = 0xffff }; /* These are the "meat" - everything else is stuffing */ @@ -1541,42 +1550,52 @@ out_bh: } /* - * udf_load_logicalvolint - * + * Find the prevailing Logical Volume Integrity Descriptor. */ static void udf_load_logicalvolint(struct super_block *sb, struct kernel_extent_ad loc) { - struct buffer_head *bh = NULL; + struct buffer_head *bh, *final_bh; uint16_t ident; struct udf_sb_info *sbi = UDF_SB(sb); struct logicalVolIntegrityDesc *lvid; + int indirections = 0; + + while (++indirections <= UDF_MAX_LVID_NESTING) { + final_bh = NULL; + while (loc.extLength > 0 && + (bh = udf_read_tagged(sb, loc.extLocation, + loc.extLocation, &ident))) { + if (ident != TAG_IDENT_LVID) { + brelse(bh); + break; + } + + brelse(final_bh); + final_bh = bh; - while (loc.extLength > 0 && - (bh = udf_read_tagged(sb, loc.extLocation, - loc.extLocation, &ident)) && - ident == TAG_IDENT_LVID) { - sbi->s_lvid_bh = bh; - lvid = (struct logicalVolIntegrityDesc *)bh->b_data; + loc.extLength -= sb->s_blocksize; + loc.extLocation++; + } - if (lvid->nextIntegrityExt.extLength) - udf_load_logicalvolint(sb, - leea_to_cpu(lvid->nextIntegrityExt)); + if (!final_bh) + return; - if (sbi->s_lvid_bh != bh) - brelse(bh); - loc.extLength -= sb->s_blocksize; - loc.extLocation++; + brelse(sbi->s_lvid_bh); + sbi->s_lvid_bh = final_bh; + + lvid = (struct logicalVolIntegrityDesc *)final_bh->b_data; + if (lvid->nextIntegrityExt.extLength == 0) + return; + + loc = leea_to_cpu(lvid->nextIntegrityExt); } - if (sbi->s_lvid_bh != bh) - brelse(bh); + + udf_warn(sb, "Too many LVID indirections (max %u), ignoring.\n", + UDF_MAX_LVID_NESTING); + brelse(sbi->s_lvid_bh); + sbi->s_lvid_bh = NULL; } -/* - * Maximum number of Terminating Descriptor redirections. The chosen number is - * arbitrary - just that we hopefully don't limit any real use of rewritten - * inode on write-once media but avoid looping for too long on corrupted media. - */ -#define UDF_MAX_TD_NESTING 64 /* * Process a main/reserve volume descriptor sequence. |
