mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-30 06:10:56 +00:00
ext4: fix leaking uninitialized memory in fast-commit journal
commit594bc43b41
upstream. When space at the end of fast-commit journal blocks is unused, make sure to zero it out so that uninitialized memory is not leaked to disk. Fixes:aa75f4d3da
("ext4: main fast-commit commit path") Cc: <stable@vger.kernel.org> # v5.10+ Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20221106224841.279231-4-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
parent
0bdcac7469
commit
d9ba03eb03
1 changed files with 5 additions and 0 deletions
|
@ -745,6 +745,9 @@ static u8 *ext4_fc_reserve_space(struct super_block *sb, int len, u32 *crc)
|
||||||
*crc = ext4_chksum(sbi, *crc, tl, EXT4_FC_TAG_BASE_LEN);
|
*crc = ext4_chksum(sbi, *crc, tl, EXT4_FC_TAG_BASE_LEN);
|
||||||
if (pad_len > 0)
|
if (pad_len > 0)
|
||||||
ext4_fc_memzero(sb, tl + 1, pad_len, crc);
|
ext4_fc_memzero(sb, tl + 1, pad_len, crc);
|
||||||
|
/* Don't leak uninitialized memory in the unused last byte. */
|
||||||
|
*((u8 *)(tl + 1) + pad_len) = 0;
|
||||||
|
|
||||||
ext4_fc_submit_bh(sb, false);
|
ext4_fc_submit_bh(sb, false);
|
||||||
|
|
||||||
ret = jbd2_fc_get_buf(EXT4_SB(sb)->s_journal, &bh);
|
ret = jbd2_fc_get_buf(EXT4_SB(sb)->s_journal, &bh);
|
||||||
|
@ -801,6 +804,8 @@ static int ext4_fc_write_tail(struct super_block *sb, u32 crc)
|
||||||
dst += sizeof(tail.fc_tid);
|
dst += sizeof(tail.fc_tid);
|
||||||
tail.fc_crc = cpu_to_le32(crc);
|
tail.fc_crc = cpu_to_le32(crc);
|
||||||
ext4_fc_memcpy(sb, dst, &tail.fc_crc, sizeof(tail.fc_crc), NULL);
|
ext4_fc_memcpy(sb, dst, &tail.fc_crc, sizeof(tail.fc_crc), NULL);
|
||||||
|
dst += sizeof(tail.fc_crc);
|
||||||
|
memset(dst, 0, bsize - off); /* Don't leak uninitialized memory. */
|
||||||
|
|
||||||
ext4_fc_submit_bh(sb, true);
|
ext4_fc_submit_bh(sb, true);
|
||||||
|
|
||||||
|
|
Loading…
Reference in a new issue