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udf: Verify domain identifier fields 

OSTA UDF standard defines that domain identifier in logical volume
descriptor and file set descriptor should contain a particular string
and the identifier suffix contains flags possibly making media
write-protected. Verify these constraints and allow only read-only mount
if they are not met.

Tested-by: Steven J. Magnani <steve@digidescorp.com>
Reviewed-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Jan Kara <jack@suse.cz>
alistair/sunxi64-5.4-dsi
Jan Kara 2019-08-29 14:11:54 +02:00
parent c3367a1b47
commit 2dee5aac05
2 changed files with 78 additions and 27 deletions
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14
fs/udf/ecma_167.h
View File

@ -88,6 +88,20 @@ struct regid {
#define ENTITYID_FLAGS_DIRTY 0x00
#define ENTITYID_FLAGS_PROTECTED 0x01
/* OSTA UDF 2.1.5.2 */
#define UDF_ID_COMPLIANT "*OSTA UDF Compliant"
/* OSTA UDF 2.1.5.3 */
struct domainEntityIDSuffix {
uint16_t revision;
uint8_t flags;
uint8_t reserved[5];
};
/* OSTA UDF 2.1.5.3 */
#define ENTITYIDSUFFIX_FLAGS_HARDWRITEPROTECT 0
#define ENTITYIDSUFFIX_FLAGS_SOFTWRITEPROTECT 1
/* Volume Structure Descriptor (ECMA 167r3 2/9.1) */
#define VSD_STD_ID_LEN 5
struct volStructDesc {

91
fs/udf/super.c
View File

@ -94,8 +94,8 @@ static int udf_remount_fs(struct super_block *, int *, char *);
static void udf_load_logicalvolint(struct super_block *, struct kernel_extent_ad);
static int udf_find_fileset(struct super_block *, struct kernel_lb_addr *,
struct kernel_lb_addr *);
static void udf_load_fileset(struct super_block *, struct buffer_head *,
struct kernel_lb_addr *);
static int udf_load_fileset(struct super_block *, struct fileSetDesc *,
struct kernel_lb_addr *);
static void udf_open_lvid(struct super_block *);
static void udf_close_lvid(struct super_block *);
static unsigned int udf_count_free(struct super_block *);
@ -775,28 +775,27 @@ static int udf_find_fileset(struct super_block *sb,
{
struct buffer_head *bh = NULL;
uint16_t ident;
int ret;
if (fileset->logicalBlockNum != 0xFFFFFFFF ||
fileset->partitionReferenceNum != 0xFFFF) {
bh = udf_read_ptagged(sb, fileset, 0, &ident);
if (fileset->logicalBlockNum == 0xFFFFFFFF &&
fileset->partitionReferenceNum == 0xFFFF)
return -EINVAL;
if (!bh) {
return 1;
} else if (ident != TAG_IDENT_FSD) {
brelse(bh);
return 1;
}
udf_debug("Fileset at block=%u, partition=%u\n",
fileset->logicalBlockNum,
fileset->partitionReferenceNum);
UDF_SB(sb)->s_partition = fileset->partitionReferenceNum;
udf_load_fileset(sb, bh, root);
bh = udf_read_ptagged(sb, fileset, 0, &ident);
if (!bh)
return -EIO;
if (ident != TAG_IDENT_FSD) {
brelse(bh);
return 0;
return -EINVAL;
}
return 1;
udf_debug("Fileset at block=%u, partition=%u\n",
fileset->logicalBlockNum, fileset->partitionReferenceNum);
UDF_SB(sb)->s_partition = fileset->partitionReferenceNum;
ret = udf_load_fileset(sb, (struct fileSetDesc *)bh->b_data, root);
brelse(bh);
return ret;
}
/*
@ -952,19 +951,53 @@ static int udf_load_metadata_files(struct super_block *sb, int partition,
return 0;
}
static void udf_load_fileset(struct super_block *sb, struct buffer_head *bh,
struct kernel_lb_addr *root)
static int udf_verify_domain_identifier(struct super_block *sb,
struct regid *ident, char *dname)
{
struct fileSetDesc *fset;
struct domainEntityIDSuffix *suffix;
fset = (struct fileSetDesc *)bh->b_data;
if (memcmp(ident->ident, UDF_ID_COMPLIANT, strlen(UDF_ID_COMPLIANT))) {
udf_warn(sb, "Not OSTA UDF compliant %s descriptor.\n", dname);
goto force_ro;
}
if (ident->flags & (1 << ENTITYID_FLAGS_DIRTY)) {
udf_warn(sb, "Possibly not OSTA UDF compliant %s descriptor.\n",
dname);
goto force_ro;
}
suffix = (struct domainEntityIDSuffix *)ident->identSuffix;
if (suffix->flags & (1 << ENTITYIDSUFFIX_FLAGS_HARDWRITEPROTECT) ||
suffix->flags & (1 << ENTITYIDSUFFIX_FLAGS_SOFTWRITEPROTECT)) {
if (!sb_rdonly(sb)) {
udf_warn(sb, "Descriptor for %s marked write protected."
" Forcing read only mount.\n", dname);
}
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_load_fileset(struct super_block *sb, struct fileSetDesc *fset,
struct kernel_lb_addr *root)
{
int ret;
ret = udf_verify_domain_identifier(sb, &fset->domainIdent, "file set");
if (ret < 0)
return ret;
*root = lelb_to_cpu(fset->rootDirectoryICB.extLocation);
UDF_SB(sb)->s_serial_number = le16_to_cpu(fset->descTag.tagSerialNum);
udf_debug("Rootdir at block=%u, partition=%u\n",
root->logicalBlockNum, root->partitionReferenceNum);
return 0;
}
int udf_compute_nr_groups(struct super_block *sb, u32 partition)
@ -1375,6 +1408,10 @@ static int udf_load_logicalvol(struct super_block *sb, sector_t block,
goto out_bh;
}
ret = udf_verify_domain_identifier(sb, &lvd->domainIdent,
"logical volume");
if (ret)
goto out_bh;
ret = udf_sb_alloc_partition_maps(sb, le32_to_cpu(lvd->numPartitionMaps));
if (ret)
goto out_bh;
@ -2227,9 +2264,9 @@ static int udf_fill_super(struct super_block *sb, void *options, int silent)
UDF_SET_FLAG(sb, UDF_FLAG_RW_INCOMPAT);
}
if (udf_find_fileset(sb, &fileset, &rootdir)) {
ret = udf_find_fileset(sb, &fileset, &rootdir);
if (ret < 0) {
udf_warn(sb, "No fileset found\n");
ret = -EINVAL;
goto error_out;
}