From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: Ritesh Harjani <riteshh@linux.ibm.com>
Cc: Murphy Zhou <jencce.kernel@gmail.com>,
Ext4 Developers List <linux-ext4@vger.kernel.org>
Subject: Re: [PATCH] ext4: validate fiemap iomap begin offset and length value
Date: Sun, 19 Apr 2020 00:46:12 -0400 [thread overview]
Message-ID: <20200419044612.GB311394@mit.edu> (raw)
In-Reply-To: <20200419044224.GA311394@mit.edu>
On Sun, Apr 19, 2020 at 12:42:24AM -0400, Theodore Y. Ts'o wrote:
> I think we need to take his patch, and make a simialr change to
> ext4_iomap_begin(). Ritesh, do you agree?
For example...
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 2a4aae6acdcb..adce3339d697 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3424,8 +3424,10 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
int ret;
struct ext4_map_blocks map;
u8 blkbits = inode->i_blkbits;
+ ext4_lblk_t lblk = offset >> blkbits;
+ ext4_lblk_t last_lblk = (offset + length - 1) >> blkbits;
- if ((offset >> blkbits) > EXT4_MAX_LOGICAL_BLOCK)
+ if (lblk > EXT4_MAX_LOGICAL_BLOCK)
return -EINVAL;
if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
@@ -3434,9 +3436,15 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
/*
* Calculate the first and last logical blocks respectively.
*/
- map.m_lblk = offset >> blkbits;
- map.m_len = min_t(loff_t, (offset + length - 1) >> blkbits,
- EXT4_MAX_LOGICAL_BLOCK) - map.m_lblk + 1;
+ if (last_lblk >= EXT4_MAX_LOGICAL_BLOCK)
+ last_lblk = EXT4_MAX_LOGICAL_BLOCK - 1;
+ if (lblk >= EXT4_MAX_LOGICAL_BLOCK)
+ lblk = EXT4_MAX_LOGICAL_BLOCK - 1;
+
+ map.m_lblk = lblk;
+ map.m_len = last_lblk - lblk + 1;
+ if (map.m_len == 0 )
+ map.m_len = 1;
if (flags & IOMAP_WRITE)
ret = ext4_iomap_alloc(inode, &map, flags);
@@ -3524,8 +3532,10 @@ static int ext4_iomap_begin_report(struct inode *inode, loff_t offset,
bool delalloc = false;
struct ext4_map_blocks map;
u8 blkbits = inode->i_blkbits;
+ ext4_lblk_t lblk = offset >> blkbits;
+ ext4_lblk_t last_lblk = (offset + length - 1) >> blkbits;
- if ((offset >> blkbits) > EXT4_MAX_LOGICAL_BLOCK)
+ if (lblk > EXT4_MAX_LOGICAL_BLOCK)
return -EINVAL;
if (ext4_has_inline_data(inode)) {
@@ -3540,9 +3550,15 @@ static int ext4_iomap_begin_report(struct inode *inode, loff_t offset,
/*
* Calculate the first and last logical block respectively.
*/
- map.m_lblk = offset >> blkbits;
- map.m_len = min_t(loff_t, (offset + length - 1) >> blkbits,
- EXT4_MAX_LOGICAL_BLOCK) - map.m_lblk + 1;
+ if (last_lblk >= EXT4_MAX_LOGICAL_BLOCK)
+ last_lblk = EXT4_MAX_LOGICAL_BLOCK - 1;
+ if (lblk >= EXT4_MAX_LOGICAL_BLOCK)
+ lblk = EXT4_MAX_LOGICAL_BLOCK - 1;
+
+ map.m_lblk = lblk;
+ map.m_len = last_lblk - lblk + 1;
+ if (map.m_len == 0 )
+ map.m_len = 1;
/*
* Fiemap callers may call for offset beyond s_bitmap_maxbytes.
next prev parent reply other threads:[~2020-04-19 4:46 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-18 23:32 [PATCH] ext4: validate fiemap iomap begin offset and length value Murphy Zhou
2020-04-19 1:56 ` Ritesh Harjani
2020-04-19 4:42 ` Theodore Y. Ts'o
2020-04-19 4:46 ` Theodore Y. Ts'o [this message]
2020-04-19 16:19 ` Ritesh Harjani
2020-04-20 2:57 ` Murphy Zhou
2020-04-20 4:16 ` Ritesh Harjani
2020-04-20 7:03 ` Ritesh Harjani
2020-04-20 7:27 ` Murphy Zhou
2020-04-20 13:48 ` Ritesh Harjani
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