diff options
Diffstat (limited to 'debian/patches/0088-fs-f2fs-Do-not-read-past-the-end-of-nat-bitmap.patch')
| -rw-r--r-- | debian/patches/0088-fs-f2fs-Do-not-read-past-the-end-of-nat-bitmap.patch | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/debian/patches/0088-fs-f2fs-Do-not-read-past-the-end-of-nat-bitmap.patch b/debian/patches/0088-fs-f2fs-Do-not-read-past-the-end-of-nat-bitmap.patch new file mode 100644 index 0000000..5f06bd4 --- /dev/null +++ b/debian/patches/0088-fs-f2fs-Do-not-read-past-the-end-of-nat-bitmap.patch @@ -0,0 +1,131 @@ +From 9561d7ef621e5e68f12bcd916252ef1c11e60366 Mon Sep 17 00:00:00 2001 +From: Sudhakar Kuppusamy <sudhakar@linux.ibm.com> +Date: Wed, 6 Apr 2022 18:49:09 +0530 +Subject: fs/f2fs: Do not read past the end of nat bitmap + +A corrupt f2fs filesystem could have a block offset or a bitmap +offset that would cause us to read beyond the bounds of the nat +bitmap. + +Introduce the nat_bitmap_size member in grub_f2fs_data which holds +the size of nat bitmap. + +Set the size when loading the nat bitmap in nat_bitmap_ptr(), and +catch when an invalid offset would create a pointer past the end of +the allocated space. + +Check against the bitmap size in grub_f2fs_test_bit() test bit to avoid +reading past the end of the nat bitmap. + +Signed-off-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com> +Signed-off-by: Daniel Axtens <dja@axtens.net> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> +--- + grub-core/fs/f2fs.c | 33 +++++++++++++++++++++++++++------ + 1 file changed, 27 insertions(+), 6 deletions(-) + +diff --git a/grub-core/fs/f2fs.c b/grub-core/fs/f2fs.c +index 63702214b..8898b235e 100644 +--- a/grub-core/fs/f2fs.c ++++ b/grub-core/fs/f2fs.c +@@ -122,6 +122,7 @@ GRUB_MOD_LICENSE ("GPLv3+"); + #define F2FS_INLINE_DOTS 0x10 /* File having implicit dot dentries. */ + + #define MAX_VOLUME_NAME 512 ++#define MAX_NAT_BITMAP_SIZE 3900 + + enum FILE_TYPE + { +@@ -183,7 +184,7 @@ struct grub_f2fs_checkpoint + grub_uint32_t checksum_offset; + grub_uint64_t elapsed_time; + grub_uint8_t alloc_type[MAX_ACTIVE_LOGS]; +- grub_uint8_t sit_nat_version_bitmap[3900]; ++ grub_uint8_t sit_nat_version_bitmap[MAX_NAT_BITMAP_SIZE]; + grub_uint32_t checksum; + } GRUB_PACKED; + +@@ -302,6 +303,7 @@ struct grub_f2fs_data + + struct grub_f2fs_nat_journal nat_j; + char *nat_bitmap; ++ grub_uint32_t nat_bitmap_size; + + grub_disk_t disk; + struct grub_f2fs_node *inode; +@@ -377,15 +379,20 @@ sum_blk_addr (struct grub_f2fs_data *data, int base, int type) + } + + static void * +-nat_bitmap_ptr (struct grub_f2fs_data *data) ++nat_bitmap_ptr (struct grub_f2fs_data *data, grub_uint32_t *nat_bitmap_size) + { + struct grub_f2fs_checkpoint *ckpt = &data->ckpt; + grub_uint32_t offset; ++ *nat_bitmap_size = MAX_NAT_BITMAP_SIZE; + + if (grub_le_to_cpu32 (data->sblock.cp_payload) > 0) + return ckpt->sit_nat_version_bitmap; + + offset = grub_le_to_cpu32 (ckpt->sit_ver_bitmap_bytesize); ++ if (offset >= MAX_NAT_BITMAP_SIZE) ++ return NULL; ++ ++ *nat_bitmap_size = *nat_bitmap_size - offset; + + return ckpt->sit_nat_version_bitmap + offset; + } +@@ -438,11 +445,15 @@ grub_f2fs_crc_valid (grub_uint32_t blk_crc, void *buf, const grub_uint32_t len) + } + + static int +-grub_f2fs_test_bit (grub_uint32_t nr, const char *p) ++grub_f2fs_test_bit (grub_uint32_t nr, const char *p, grub_uint32_t len) + { + int mask; ++ grub_uint32_t shifted_nr = (nr >> 3); ++ ++ if (shifted_nr >= len) ++ return -1; + +- p += (nr >> 3); ++ p += shifted_nr; + mask = 1 << (7 - (nr & 0x07)); + + return mask & *p; +@@ -662,6 +673,7 @@ get_node_blkaddr (struct grub_f2fs_data *data, grub_uint32_t nid) + grub_uint32_t seg_off, block_off, entry_off, block_addr; + grub_uint32_t blkaddr = 0; + grub_err_t err; ++ int result_bit; + + err = get_blkaddr_from_nat_journal (data, nid, &blkaddr); + if (err != GRUB_ERR_NONE) +@@ -682,8 +694,15 @@ get_node_blkaddr (struct grub_f2fs_data *data, grub_uint32_t nid) + ((seg_off * data->blocks_per_seg) << 1) + + (block_off & (data->blocks_per_seg - 1)); + +- if (grub_f2fs_test_bit (block_off, data->nat_bitmap)) ++ result_bit = grub_f2fs_test_bit (block_off, data->nat_bitmap, ++ data->nat_bitmap_size); ++ if (result_bit > 0) + block_addr += data->blocks_per_seg; ++ else if (result_bit == -1) ++ { ++ grub_free (nat_block); ++ return 0; ++ } + + err = grub_f2fs_block_read (data, block_addr, nat_block); + if (err) +@@ -833,7 +852,9 @@ grub_f2fs_mount (grub_disk_t disk) + if (err) + goto fail; + +- data->nat_bitmap = nat_bitmap_ptr (data); ++ data->nat_bitmap = nat_bitmap_ptr (data, &data->nat_bitmap_size); ++ if (data->nat_bitmap == NULL) ++ goto fail; + + err = get_nat_journal (data); + if (err) |