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authorChandan Rajendra <chandan@linux.vnet.ibm.com>2016-11-14 21:26:26 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-06 11:16:12 +0100
commit7b74c351de1c135faf6f80226dedf3aba697464a (patch)
tree3c4defec999c633312e019601020a6d9509bd88a
parent26492d8a22b013df435eadd91eeba2c8701206f6 (diff)
ext4: fix stack memory corruption with 64k block size
commit 30a9d7afe70ed6bd9191d3000e2ef1a34fb58493 upstream. The number of 'counters' elements needed in 'struct sg' is super_block->s_blocksize_bits + 2. Presently we have 16 'counters' elements in the array. This is insufficient for block sizes >= 32k. In such cases the memcpy operation performed in ext4_mb_seq_groups_show() would cause stack memory corruption. Fixes: c9de560ded61f Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/ext4/mballoc.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 748dec05ec7b..b7a3957a9dca 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2287,7 +2287,7 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
struct ext4_group_info *grinfo;
struct sg {
struct ext4_group_info info;
- ext4_grpblk_t counters[16];
+ ext4_grpblk_t counters[EXT4_MAX_BLOCK_LOG_SIZE + 2];
} sg;
group--;