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-rw-r--r--exfat/libexfat/mount.c112
1 files changed, 77 insertions, 35 deletions
diff --git a/exfat/libexfat/mount.c b/exfat/libexfat/mount.c
index 928c561dc..0d6ce9ead 100644
--- a/exfat/libexfat/mount.c
+++ b/exfat/libexfat/mount.c
@@ -3,7 +3,7 @@
exFAT file system implementation library.
Free exFAT implementation.
- Copyright (C) 2010-2013 Andrew Nayenko
+ Copyright (C) 2010-2015 Andrew Nayenko
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -24,22 +24,38 @@
#include <string.h>
#include <stdlib.h>
#include <errno.h>
+#include <inttypes.h>
#include <unistd.h>
#include <sys/types.h>
static uint64_t rootdir_size(const struct exfat* ef)
{
- uint64_t clusters = 0;
+ uint32_t clusters = 0;
+ uint32_t clusters_max = le32_to_cpu(ef->sb->cluster_count);
cluster_t rootdir_cluster = le32_to_cpu(ef->sb->rootdir_cluster);
- while (!CLUSTER_INVALID(rootdir_cluster))
+ /* Iterate all clusters of the root directory to calculate its size.
+ It can't be contiguous because there is no flag to indicate this. */
+ do
{
- clusters++;
- /* root directory cannot be contiguous because there is no flag
- to indicate this */
+ if (clusters == clusters_max) /* infinite loop detected */
+ {
+ exfat_error("root directory cannot occupy all %d clusters",
+ clusters);
+ return 0;
+ }
+ if (CLUSTER_INVALID(rootdir_cluster))
+ {
+ exfat_error("bad cluster %#x while reading root directory",
+ rootdir_cluster);
+ return 0;
+ }
rootdir_cluster = exfat_next_cluster(ef, ef->root, rootdir_cluster);
+ clusters++;
}
- return clusters * CLUSTER_SIZE(*ef->sb);
+ while (rootdir_cluster != EXFAT_CLUSTER_END);
+
+ return (uint64_t) clusters * CLUSTER_SIZE(*ef->sb);
}
static const char* get_option(const char* options, const char* option_name)
@@ -77,13 +93,11 @@ static bool match_option(const char* options, const char* option_name)
static void parse_options(struct exfat* ef, const char* options)
{
- int sys_umask = umask(0);
int opt_umask;
- umask(sys_umask); /* restore umask */
- opt_umask = get_int_option(options, "umask", 8, sys_umask);
- ef->dmask = get_int_option(options, "dmask", 8, opt_umask) & 0777;
- ef->fmask = get_int_option(options, "fmask", 8, opt_umask) & 0777;
+ opt_umask = get_int_option(options, "umask", 8, 0);
+ ef->dmask = get_int_option(options, "dmask", 8, opt_umask);
+ ef->fmask = get_int_option(options, "fmask", 8, opt_umask);
ef->uid = get_int_option(options, "uid", 10, geteuid());
ef->gid = get_int_option(options, "gid", 10, getegid());
@@ -91,8 +105,8 @@ static void parse_options(struct exfat* ef, const char* options)
ef->noatime = match_option(options, "noatime");
}
-static int verify_vbr_checksum(struct exfat_dev* dev, void* sector,
- off64_t sector_size)
+static bool verify_vbr_checksum(struct exfat_dev* dev, void* sector,
+ off_t sector_size)
{
uint32_t vbr_checksum;
int i;
@@ -100,7 +114,7 @@ static int verify_vbr_checksum(struct exfat_dev* dev, void* sector,
if (exfat_pread(dev, sector, sector_size, 0) < 0)
{
exfat_error("failed to read boot sector");
- return 1;
+ return false;
}
vbr_checksum = exfat_vbr_start_checksum(sector, sector_size);
for (i = 1; i < 11; i++)
@@ -108,7 +122,7 @@ static int verify_vbr_checksum(struct exfat_dev* dev, void* sector,
if (exfat_pread(dev, sector, sector_size, i * sector_size) < 0)
{
exfat_error("failed to read VBR sector");
- return 1;
+ return false;
}
vbr_checksum = exfat_vbr_add_checksum(sector, sector_size,
vbr_checksum);
@@ -116,16 +130,16 @@ static int verify_vbr_checksum(struct exfat_dev* dev, void* sector,
if (exfat_pread(dev, sector, sector_size, i * sector_size) < 0)
{
exfat_error("failed to read VBR checksum sector");
- return 1;
+ return false;
}
for (i = 0; i < sector_size / sizeof(vbr_checksum); i++)
if (le32_to_cpu(((const le32_t*) sector)[i]) != vbr_checksum)
{
exfat_error("invalid VBR checksum 0x%x (expected 0x%x)",
le32_to_cpu(((const le32_t*) sector)[i]), vbr_checksum);
- return 1;
+ return false;
}
- return 0;
+ return true;
}
static int commit_super_block(const struct exfat* ef)
@@ -201,31 +215,23 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
exfat_error("exFAT file system is not found");
return -EIO;
}
- if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
+ /* sector cannot be smaller than 512 bytes */
+ if (ef->sb->sector_bits < 9)
{
exfat_close(ef->dev);
- exfat_error("unsupported exFAT version: %hhu.%hhu",
- ef->sb->version.major, ef->sb->version.minor);
+ exfat_error("too small sector size: 2^%hhd", ef->sb->sector_bits);
free(ef->sb);
return -EIO;
}
- if (ef->sb->fat_count != 1)
- {
- exfat_close(ef->dev);
- free(ef->sb);
- exfat_error("unsupported FAT count: %hhu", ef->sb->fat_count);
- return -EIO;
- }
/* officially exFAT supports cluster size up to 32 MB */
if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
{
exfat_close(ef->dev);
+ exfat_error("too big cluster size: 2^(%hhd+%hhd)",
+ ef->sb->sector_bits, ef->sb->spc_bits);
free(ef->sb);
- exfat_error("too big cluster size: 2^%d",
- (int) ef->sb->sector_bits + (int) ef->sb->spc_bits);
return -EIO;
}
-
ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
if (ef->zero_cluster == NULL)
{
@@ -235,8 +241,7 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
return -ENOMEM;
}
/* use zero_cluster as a temporary buffer for VBR checksum verification */
- if (verify_vbr_checksum(ef->dev, ef->zero_cluster,
- SECTOR_SIZE(*ef->sb)) != 0)
+ if (!verify_vbr_checksum(ef->dev, ef->zero_cluster, SECTOR_SIZE(*ef->sb)))
{
free(ef->zero_cluster);
exfat_close(ef->dev);
@@ -244,6 +249,33 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
return -EIO;
}
memset(ef->zero_cluster, 0, CLUSTER_SIZE(*ef->sb));
+ if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
+ {
+ free(ef->zero_cluster);
+ exfat_close(ef->dev);
+ exfat_error("unsupported exFAT version: %hhu.%hhu",
+ ef->sb->version.major, ef->sb->version.minor);
+ free(ef->sb);
+ return -EIO;
+ }
+ if (ef->sb->fat_count != 1)
+ {
+ free(ef->zero_cluster);
+ exfat_close(ef->dev);
+ exfat_error("unsupported FAT count: %hhu", ef->sb->fat_count);
+ free(ef->sb);
+ return -EIO;
+ }
+ if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) >
+ exfat_get_size(ef->dev))
+ {
+ /* this can cause I/O errors later but we don't fail mounting to let
+ user rescue data */
+ exfat_warn("file system is larger than underlying device: "
+ "%"PRIu64" > %"PRIu64,
+ le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb),
+ exfat_get_size(ef->dev));
+ }
ef->root = malloc(sizeof(struct exfat_node));
if (ef->root == NULL)
@@ -260,6 +292,14 @@ int exfat_mount(struct exfat* ef, const char* spec, const char* options)
ef->root->fptr_cluster = ef->root->start_cluster;
ef->root->name[0] = cpu_to_le16('\0');
ef->root->size = rootdir_size(ef);
+ if (ef->root->size == 0)
+ {
+ free(ef->root);
+ free(ef->zero_cluster);
+ exfat_close(ef->dev);
+ free(ef->sb);
+ return -EIO;
+ }
/* exFAT does not have time attributes for the root directory */
ef->root->mtime = 0;
ef->root->atime = 0;
@@ -314,11 +354,13 @@ static void finalize_super_block(struct exfat* ef)
ef->sb->allocated_percent = ((total - free) * 100 + total / 2) / total;
}
- commit_super_block(ef);
+ commit_super_block(ef); /* ignore return code */
}
void exfat_unmount(struct exfat* ef)
{
+ exfat_flush_nodes(ef); /* ignore return code */
+ exfat_flush(ef); /* ignore return code */
exfat_put_node(ef, ef->root);
exfat_reset_cache(ef);
free(ef->root);
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-03 18:17:45 +0200