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authorJan Kara <jack@suse.cz>2018-09-06 15:46:17 +0200
committerJan Kara <jack@suse.cz>2018-09-07 10:32:22 +0200
commitb085fbe2ef7fa7489903c45271ae7b7a52b0f9ab (patch)
treeae5f90c244fc54daf94d51f56bb9c144562ecaad /fs/udf
parenta9ad01bc759df79b0012f43ee52164391e31cd96 (diff)
downloadlinux-b085fbe2ef7fa7489903c45271ae7b7a52b0f9ab.tar.bz2
udf: Fix crash during mount
Fix a crash during an attempt to mount a filesystem that has both Unallocated Space Table and Unallocated Space Bitmap. Such filesystem actually violates the UDF standard so we just have to properly detect such situation and refuse to mount such filesystem read-write. When we are at it, verify also other constraints on the allocation information mandated by the standard. Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/udf')
-rw-r--r--fs/udf/super.c65
1 files changed, 60 insertions, 5 deletions
diff --git a/fs/udf/super.c b/fs/udf/super.c
index b997e3116e37..be934bcfa24b 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -985,12 +985,62 @@ static struct udf_bitmap *udf_sb_alloc_bitmap(struct super_block *sb, u32 index)
return bitmap;
}
+static int check_partition_desc(struct super_block *sb,
+ struct partitionDesc *p,
+ struct udf_part_map *map)
+{
+ bool umap, utable, fmap, ftable;
+ struct partitionHeaderDesc *phd;
+
+ switch (le32_to_cpu(p->accessType)) {
+ case PD_ACCESS_TYPE_READ_ONLY:
+ case PD_ACCESS_TYPE_WRITE_ONCE:
+ case PD_ACCESS_TYPE_REWRITABLE:
+ case PD_ACCESS_TYPE_NONE:
+ goto force_ro;
+ }
+
+ /* No Partition Header Descriptor? */
+ if (strcmp(p->partitionContents.ident, PD_PARTITION_CONTENTS_NSR02) &&
+ strcmp(p->partitionContents.ident, PD_PARTITION_CONTENTS_NSR03))
+ goto force_ro;
+
+ phd = (struct partitionHeaderDesc *)p->partitionContentsUse;
+ utable = phd->unallocSpaceTable.extLength;
+ umap = phd->unallocSpaceBitmap.extLength;
+ ftable = phd->freedSpaceTable.extLength;
+ fmap = phd->freedSpaceBitmap.extLength;
+
+ /* No allocation info? */
+ if (!utable && !umap && !ftable && !fmap)
+ goto force_ro;
+
+ /* We don't support blocks that require erasing before overwrite */
+ if (ftable || fmap)
+ goto force_ro;
+ /* UDF 2.60: 2.3.3 - no mixing of tables & bitmaps, no VAT. */
+ if (utable && umap)
+ goto force_ro;
+
+ if (map->s_partition_type == UDF_VIRTUAL_MAP15 ||
+ map->s_partition_type == UDF_VIRTUAL_MAP20)
+ goto force_ro;
+
+ return 0;
+force_ro:
+ if (!sb_rdonly(sb))
+ return -EACCES;
+ UDF_SET_FLAG(sb, UDF_FLAG_RW_INCOMPAT);
+ return 0;
+}
+
static int udf_fill_partdesc_info(struct super_block *sb,
struct partitionDesc *p, int p_index)
{
struct udf_part_map *map;
struct udf_sb_info *sbi = UDF_SB(sb);
struct partitionHeaderDesc *phd;
+ int err;
map = &sbi->s_partmaps[p_index];
@@ -1010,8 +1060,16 @@ static int udf_fill_partdesc_info(struct super_block *sb,
p_index, map->s_partition_type,
map->s_partition_root, map->s_partition_len);
- if (strcmp(p->partitionContents.ident, PD_PARTITION_CONTENTS_NSR02) &&
- strcmp(p->partitionContents.ident, PD_PARTITION_CONTENTS_NSR03))
+ err = check_partition_desc(sb, p, map);
+ if (err)
+ return err;
+
+ /*
+ * Skip loading allocation info it we cannot ever write to the fs.
+ * This is a correctness thing as we may have decided to force ro mount
+ * to avoid allocation info we don't support.
+ */
+ if (UDF_QUERY_FLAG(sb, UDF_FLAG_RW_INCOMPAT))
return 0;
phd = (struct partitionHeaderDesc *)p->partitionContentsUse;
@@ -1047,9 +1105,6 @@ static int udf_fill_partdesc_info(struct super_block *sb,
p_index, bitmap->s_extPosition);
}
- if (phd->partitionIntegrityTable.extLength)
- udf_debug("partitionIntegrityTable (part %d)\n", p_index);
-
if (phd->freedSpaceTable.extLength) {
struct kernel_lb_addr loc = {
.logicalBlockNum = le32_to_cpu(