http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-1577
Patch attached.
Cheers,
Moritz
commit 3eb8e74ec72736b9b9d728bad30484ec89c91dde
Author: Timo Warns <[email protected]>
Date: Thu May 26 16:25:57 2011 -0700
fs/partitions/efi.c: corrupted GUID partition tables can cause kernel oops
The kernel automatically evaluates partition tables of storage devices.
The code for evaluating GUID partitions (in fs/partitions/efi.c) contains
a bug that causes a kernel oops on certain corrupted GUID partition
tables.
This bug has security impacts, because it allows, for example, to
prepare a storage device that crashes a kernel subsystem upon connecting
the device (e.g., a "USB Stick of (Partial) Death").
crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size));
computes a CRC32 checksum over gpt covering (*gpt)->header_size bytes.
There is no validation of (*gpt)->header_size before the efi_crc32 call.
A corrupted partition table may have large values for (*gpt)->header_size.
In this case, the CRC32 computation access memory beyond the memory
allocated for gpt, which may cause a kernel heap overflow.
Validate value of GUID partition table header size.
[[email protected]: fix layout and indenting]
Signed-off-by: Timo Warns <[email protected]>
Cc: Matt Domsch <[email protected]>
Cc: Eugene Teo <[email protected]>
Cc: Dave Jones <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
[dannf: backported to Debian's 2.6.32]
diff --git a/fs/partitions/efi.c b/fs/partitions/efi.c
index 19d6750..6296b40 100644
--- a/fs/partitions/efi.c
+++ b/fs/partitions/efi.c
@@ -310,6 +310,15 @@ static int is_gpt_valid(struct block_device *bdev, u64 lba,gpt_he
goto fail;
}
+ /* Check the GUID Partition Table header size */
+ if (le32_to_cpu((*gpt)->header_size) >
+ bdev_logical_block_size(bdev)) {
+ pr_debug("GUID Partition Table Header size is wrong: %u > %u\n",
+ le32_to_cpu((*gpt)->header_size),
+ bdev_logical_block_size(bdev));
+ goto fail;
+ }
+
/* Check the GUID Partition Table CRC */
origcrc = le32_to_cpu((*gpt)->header_crc32);
(*gpt)->header_crc32 = 0;
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