From: Anirudh Rayabharam <mail@anirudhrb.com>
To: "Theodore Ts'o" <tytso@mit.edu>,
Andreas Dilger <adilger.kernel@dilger.ca>,
Dave Kleikamp <shaggy@austin.ibm.com>,
Alex Tomas <alex@clusterfs.com>, Andrew Morton <akpm@osdl.org>
Cc: gregkh@linuxfoundation.org,
linux-kernel-mentees@lists.linuxfoundation.org,
Anirudh Rayabharam <mail@anirudhrb.com>,
syzbot+2dcfeaf8cb49b05e8f1a@syzkaller.appspotmail.com,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] ext4: fix kernel infoleak via ext4_extent_header
Date: Fri, 7 May 2021 00:26:54 +0530 [thread overview]
Message-ID: <20210506185655.7118-1-mail@anirudhrb.com> (raw)
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
Fixes: a86c61812637 ("[PATCH] ext3: add extent map support")
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
---
Changes in v2:
Added a "Fixes:" tag.
v1: https://lore.kernel.org/lkml/20210505133011.32484-1-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
WARNING: multiple messages have this Message-ID (diff)
From: Anirudh Rayabharam <mail@anirudhrb.com>
To: "Theodore Ts'o" <tytso@mit.edu>,
Andreas Dilger <adilger.kernel@dilger.ca>,
Dave Kleikamp <shaggy@austin.ibm.com>,
Alex Tomas <alex@clusterfs.com>, Andrew Morton <akpm@osdl.org>
Cc: linux-kernel@vger.kernel.org,
syzbot+2dcfeaf8cb49b05e8f1a@syzkaller.appspotmail.com,
linux-ext4@vger.kernel.org,
linux-kernel-mentees@lists.linuxfoundation.org
Subject: [PATCH v2] ext4: fix kernel infoleak via ext4_extent_header
Date: Fri, 7 May 2021 00:26:54 +0530 [thread overview]
Message-ID: <20210506185655.7118-1-mail@anirudhrb.com> (raw)
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
Fixes: a86c61812637 ("[PATCH] ext3: add extent map support")
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
---
Changes in v2:
Added a "Fixes:" tag.
v1: https://lore.kernel.org/lkml/20210505133011.32484-1-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
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next reply other threads:[~2021-05-06 18:57 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-06 18:56 Anirudh Rayabharam [this message]
2021-05-06 18:56 ` [PATCH v2] ext4: fix kernel infoleak via ext4_extent_header Anirudh Rayabharam
2021-06-16 23:45 ` Theodore Ts'o
2021-06-16 23:45 ` Theodore Ts'o
2022-09-08 23:11 ` [PATCH] " eadavis
2022-12-26 14:31 ` How can this fix prevent information from leaking to user space and prevent the kernel from crashing? Lizhi Xu
2022-12-26 14:31 ` Lizhi Xu
2022-12-29 20:30 ` Eric Biggers
2022-12-29 20:30 ` Eric Biggers
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