| Date | Sun, 05 Feb 2012 23:10:04 +0100 | From | Willy Tarreau <> | Subject | [PATCH 15/91] Fix corrupted OSF partition table parsing |
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2.6.27-longterm review patch. If anyone has any objections, please let us know.
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commit 1eafbfeb7bdf59cfe173304c76188f3fd5f1fd05 upstream.
The kernel automatically evaluates partition tables of storage devices. The code for evaluating OSF partitions contains a bug that leaks data from kernel heap memory to userspace for certain corrupted OSF partitions.
In more detail:
for (i = 0 ; i < le16_to_cpu(label->d_npartitions); i++, partition++) {
iterates from 0 to d_npartitions - 1, where d_npartitions is read from the partition table without validation and partition is a pointer to an array of at most 8 d_partitions.
Add the proper and obvious validation.
Signed-off-by: Timo Warns <warns@pre-sense.de> Cc: stable@kernel.org [ Changed the patch trivially to not repeat the whole le16_to_cpu() thing, and to use an explicit constant for the magic value '8' ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- fs/partitions/osf.c | 12 ++++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-)
Index: longterm-2.6.27/fs/partitions/osf.c =================================================================== --- longterm-2.6.27.orig/fs/partitions/osf.c 2012-02-05 22:34:34.555915472 +0100 +++ longterm-2.6.27/fs/partitions/osf.c 2012-02-05 22:34:37.034915210 +0100 @@ -10,10 +10,13 @@ #include "check.h" #include "osf.h" +#define MAX_OSF_PARTITIONS 8 + int osf_partition(struct parsed_partitions *state, struct block_device *bdev) { int i; int slot = 1; + unsigned int npartitions; Sector sect; unsigned char *data; struct disklabel { @@ -45,7 +48,7 @@ u8 p_fstype; u8 p_frag; __le16 p_cpg; - } d_partitions[8]; + } d_partitions[MAX_OSF_PARTITIONS]; } * label; struct d_partition * partition; @@ -63,7 +66,12 @@ put_dev_sector(sect); return 0; } - for (i = 0 ; i < le16_to_cpu(label->d_npartitions); i++, partition++) { + npartitions = le16_to_cpu(label->d_npartitions); + if (npartitions > MAX_OSF_PARTITIONS) { + put_dev_sector(sect); + return 0; + } + for (i = 0 ; i < npartitions; i++, partition++) { if (slot == state->limit) break; if (le32_to_cpu(partition->p_size))
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