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authorJoern Engel <joern@logfs.org>2010-04-13 15:54:27 (GMT)
committerJoern Engel <joern@logfs.org>2010-04-13 15:54:27 (GMT)
commitd3a03f8031000f8297823b80e36db536fd020884 (patch)
treed717a209e3cf2695d1a08c104296d0bd4544ee41 /fs/logfs
parent032d8f7268444a0f5d4ee02d9513d682d5b8edfc (diff)
downloadlinux-d3a03f8031000f8297823b80e36db536fd020884.tar.xz
[LogFS] Plug 8 byte information leak
Within each journal segment, 8 bytes at offset 24 would remain uninitialized. Signed-off-by: Joern Engel <joern@logfs.org>
Diffstat (limited to 'fs/logfs')
-rw-r--r--fs/logfs/journal.c24
1 files changed, 14 insertions, 10 deletions
diff --git a/fs/logfs/journal.c b/fs/logfs/journal.c
index 2c22a4a..2957bfc 100644
--- a/fs/logfs/journal.c
+++ b/fs/logfs/journal.c
@@ -388,7 +388,10 @@ static void journal_get_erase_count(struct logfs_area *area)
static int journal_erase_segment(struct logfs_area *area)
{
struct super_block *sb = area->a_sb;
- struct logfs_segment_header sh;
+ union {
+ struct logfs_segment_header sh;
+ unsigned char c[ALIGN(sizeof(struct logfs_segment_header), 16)];
+ } u;
u64 ofs;
int err;
@@ -396,20 +399,21 @@ static int journal_erase_segment(struct logfs_area *area)
if (err)
return err;
- sh.pad = 0;
- sh.type = SEG_JOURNAL;
- sh.level = 0;
- sh.segno = cpu_to_be32(area->a_segno);
- sh.ec = cpu_to_be32(area->a_erase_count);
- sh.gec = cpu_to_be64(logfs_super(sb)->s_gec);
- sh.crc = logfs_crc32(&sh, sizeof(sh), 4);
+ memset(&u, 0, sizeof(u));
+ u.sh.pad = 0;
+ u.sh.type = SEG_JOURNAL;
+ u.sh.level = 0;
+ u.sh.segno = cpu_to_be32(area->a_segno);
+ u.sh.ec = cpu_to_be32(area->a_erase_count);
+ u.sh.gec = cpu_to_be64(logfs_super(sb)->s_gec);
+ u.sh.crc = logfs_crc32(&u.sh, sizeof(u.sh), 4);
/* This causes a bug in segment.c. Not yet. */
//logfs_set_segment_erased(sb, area->a_segno, area->a_erase_count, 0);
ofs = dev_ofs(sb, area->a_segno, 0);
- area->a_used_bytes = ALIGN(sizeof(sh), 16);
- logfs_buf_write(area, ofs, &sh, sizeof(sh));
+ area->a_used_bytes = sizeof(u);
+ logfs_buf_write(area, ofs, &u, sizeof(u));
return 0;
}