* [PATCH] ext4: fix kernel infoleak via ext4_extent_header
@ 2021-05-05 13:30 Anirudh Rayabharam
2021-05-05 16:19 ` Eric Biggers
0 siblings, 1 reply; 3+ messages in thread
From: Anirudh Rayabharam @ 2021-05-05 13:30 UTC (permalink / raw)
To: Theodore Ts'o, Andreas Dilger
Cc: gregkh, linux-kernel-mentees, Anirudh Rayabharam,
syzbot+2dcfeaf8cb49b05e8f1a, linux-ext4, linux-kernel
Initialize eh_generation of struct ext4_extent_header to prevent leaking
info to userspace. Fixes KMSAN kernel-infoleak bug reported by syzbot at:
http://syzkaller.appspot.com/bug?id=78e9ad0e6952a3ca16e8234724b2fa92d041b9b8
Reported-by: syzbot+2dcfeaf8cb49b05e8f1a@syzkaller.appspotmail.com
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
---
fs/ext4/extents.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 77c84d6f1af6..677d4821bcc1 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -825,6 +825,7 @@ void ext4_ext_tree_init(handle_t *handle, struct inode *inode)
eh->eh_entries = 0;
eh->eh_magic = EXT4_EXT_MAGIC;
eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
+ eh->eh_generation = 0;
ext4_mark_inode_dirty(handle, inode);
}
@@ -1090,6 +1091,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
neh->eh_magic = EXT4_EXT_MAGIC;
neh->eh_depth = 0;
+ neh->eh_generation = 0;
/* move remainder of path[depth] to the new leaf */
if (unlikely(path[depth].p_hdr->eh_entries !=
@@ -1167,6 +1169,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
neh->eh_magic = EXT4_EXT_MAGIC;
neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
neh->eh_depth = cpu_to_le16(depth - i);
+ neh->eh_generation = 0;
fidx = EXT_FIRST_INDEX(neh);
fidx->ei_block = border;
ext4_idx_store_pblock(fidx, oldblock);
--
2.26.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] ext4: fix kernel infoleak via ext4_extent_header
2021-05-05 13:30 [PATCH] ext4: fix kernel infoleak via ext4_extent_header Anirudh Rayabharam
@ 2021-05-05 16:19 ` Eric Biggers
2021-05-06 18:58 ` Anirudh Rayabharam
0 siblings, 1 reply; 3+ messages in thread
From: Eric Biggers @ 2021-05-05 16:19 UTC (permalink / raw)
To: Anirudh Rayabharam
Cc: Theodore Ts'o, Andreas Dilger, gregkh, linux-kernel-mentees,
syzbot+2dcfeaf8cb49b05e8f1a, linux-ext4, linux-kernel
On Wed, May 05, 2021 at 07:00:10PM +0530, Anirudh Rayabharam wrote:
> Initialize eh_generation of struct ext4_extent_header to prevent leaking
> info to userspace. Fixes KMSAN kernel-infoleak bug reported by syzbot at:
> http://syzkaller.appspot.com/bug?id=78e9ad0e6952a3ca16e8234724b2fa92d041b9b8
>
> Reported-by: syzbot+2dcfeaf8cb49b05e8f1a@syzkaller.appspotmail.com
> Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Can you include a "Fixes:" tag?
- Eric
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ext4: fix kernel infoleak via ext4_extent_header
2021-05-05 16:19 ` Eric Biggers
@ 2021-05-06 18:58 ` Anirudh Rayabharam
0 siblings, 0 replies; 3+ messages in thread
From: Anirudh Rayabharam @ 2021-05-06 18:58 UTC (permalink / raw)
To: Eric Biggers
Cc: Theodore Ts'o, Andreas Dilger, gregkh, linux-kernel-mentees,
syzbot+2dcfeaf8cb49b05e8f1a, linux-ext4, linux-kernel
On Wed, May 05, 2021 at 09:19:44AM -0700, Eric Biggers wrote:
> On Wed, May 05, 2021 at 07:00:10PM +0530, Anirudh Rayabharam wrote:
> > Initialize eh_generation of struct ext4_extent_header to prevent leaking
> > info to userspace. Fixes KMSAN kernel-infoleak bug reported by syzbot at:
> > http://syzkaller.appspot.com/bug?id=78e9ad0e6952a3ca16e8234724b2fa92d041b9b8
> >
> > Reported-by: syzbot+2dcfeaf8cb49b05e8f1a@syzkaller.appspotmail.com
> > Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
>
> Can you include a "Fixes:" tag?
Sent v2!
Thanks!
- Anirudh.
>
> - Eric
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-05-06 18:58 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-05 13:30 [PATCH] ext4: fix kernel infoleak via ext4_extent_header Anirudh Rayabharam
2021-05-05 16:19 ` Eric Biggers
2021-05-06 18:58 ` Anirudh Rayabharam
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).