From 1eafbfeb7bdf59cfe173304c76188f3fd5f1fd05 Mon Sep 17 00:00:00 2001 From: Timo Warns Date: Mon, 14 Mar 2011 14:59:33 +0100 Subject: [PATCH] Fix corrupted OSF partition table parsing 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 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 --- fs/partitions/osf.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/partitions/osf.c b/fs/partitions/osf.c index 48cec7cbca17..be03a0b08b47 100644 --- a/fs/partitions/osf.c +++ b/fs/partitions/osf.c @@ -10,10 +10,13 @@ #include "check.h" #include "osf.h" +#define MAX_OSF_PARTITIONS 8 + int osf_partition(struct parsed_partitions *state) { int i; int slot = 1; + unsigned int npartitions; Sector sect; unsigned char *data; struct disklabel { @@ -45,7 +48,7 @@ int osf_partition(struct parsed_partitions *state) 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 @@ int osf_partition(struct parsed_partitions *state) 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)) -- 2.30.2