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* grub-core/fs/ntfs.c (read_data): Prevent overflow.

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(read_attr): Ensure that we read start of possibly compressed block.
This commit is contained in:
Vladimir 'phcoder' Serbinenko 2012-05-15 17:17:06 +02:00
parent e28e5fe519
commit c6666ba687
2 changed files with 13 additions and 2 deletions
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5
ChangeLog
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@ -1,3 +1,8 @@
2012-05-15 Vladimir Serbinenko <phcoder@gmail.com>
* grub-core/fs/ntfs.c (read_data): Prevent overflow.
(read_attr): Ensure that we read start of possibly compressed block.
2012-05-15 Vladimir Serbinenko <phcoder@gmail.com>
* include/grub/ntfs.h (grub_ntfs_comp_table_element): New struct.

10
grub-core/fs/ntfs.c
View file

@ -441,7 +441,7 @@ read_data (struct grub_ntfs_attr *at, char *pa, char *dest,
}
vcn = ctx->target_vcn = (ofs >> GRUB_NTFS_COM_LOG_LEN) * (GRUB_NTFS_COM_SEC / ctx->comp.spc);
ctx->target_vcn &= ~0xF;
ctx->target_vcn &= ~0xFULL;
}
else
vcn = ctx->target_vcn = grub_divmod64 (ofs >> GRUB_NTFS_BLK_SHR, ctx->comp.spc, 0);
@ -513,7 +513,13 @@ read_attr (struct grub_ntfs_attr *at, char *dest, grub_disk_addr_t ofs,
char *pa;
grub_disk_addr_t vcn;
vcn = grub_divmod64 (ofs, at->mft->data->spc << GRUB_NTFS_BLK_SHR, 0);
/* If compression is possible make sure that we include possible
compressed block size. */
if (GRUB_NTFS_COM_SEC >= at->mft->data->spc)
vcn = ((ofs >> GRUB_NTFS_COM_LOG_LEN)
* (GRUB_NTFS_COM_SEC / at->mft->data->spc)) & ~0xFULL;
else
vcn = grub_divmod64 (ofs, at->mft->data->spc << GRUB_NTFS_BLK_SHR, 0);
pa = at->attr_nxt + u16at (at->attr_nxt, 4);
while (pa < at->attr_end)
{