linux-kernel - [PATCH] f2fs: fix to seek incorrect data offset in inline data file

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Date:   Mon, 2 Nov 2020 17:36:58 +0800
From:   Chao Yu <yuchao0@...wei.com>
To:     <jaegeuk@...nel.org>
CC:     <linux-f2fs-devel@...ts.sourceforge.net>,
        <linux-kernel@...r.kernel.org>, <chao@...nel.org>,
        Chao Yu <yuchao0@...wei.com>,
        kitestramuort <kitestramuort@...istici.org>
Subject: [PATCH] f2fs: fix to seek incorrect data offset in inline data file

As kitestramuort reported:

F2FS-fs (nvme0n1p4): access invalid blkaddr:1598541474
[   25.725898] ------------[ cut here ]------------
[   25.725903] WARNING: CPU: 6 PID: 2018 at f2fs_is_valid_blkaddr+0x23a/0x250
[   25.725923] Call Trace:
[   25.725927]  ? f2fs_llseek+0x204/0x620
[   25.725929]  ? ovl_copy_up_data+0x14f/0x200
[   25.725931]  ? ovl_copy_up_inode+0x174/0x1e0
[   25.725933]  ? ovl_copy_up_one+0xa22/0xdf0
[   25.725936]  ? ovl_copy_up_flags+0xa6/0xf0
[   25.725938]  ? ovl_aio_cleanup_handler+0xd0/0xd0
[   25.725939]  ? ovl_maybe_copy_up+0x86/0xa0
[   25.725941]  ? ovl_open+0x22/0x80
[   25.725943]  ? do_dentry_open+0x136/0x350
[   25.725945]  ? path_openat+0xb7e/0xf40
[   25.725947]  ? __check_sticky+0x40/0x40
[   25.725948]  ? do_filp_open+0x70/0x100
[   25.725950]  ? __check_sticky+0x40/0x40
[   25.725951]  ? __check_sticky+0x40/0x40
[   25.725953]  ? __x64_sys_openat+0x1db/0x2c0
[   25.725955]  ? do_syscall_64+0x2d/0x40
[   25.725957]  ? entry_SYSCALL_64_after_hwframe+0x44/0xa9

llseek() reports invalid block address access, the root cause is if
file has inline data, f2fs_seek_block() will access inline data regard
as block address index in inode block, which should be wrong, fix it.

Reported-by: kitestramuort <kitestramuort@...istici.org>
Signed-off-by: Chao Yu <yuchao0@...wei.com>
---
 fs/f2fs/file.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index d898f1e2764b..89c451f09344 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -413,9 +413,14 @@ static loff_t f2fs_seek_block(struct file *file, loff_t offset, int whence)
 		goto fail;
 
 	/* handle inline data case */
-	if (f2fs_has_inline_data(inode) && whence == SEEK_HOLE) {
-		data_ofs = isize;
-		goto found;
+	if (f2fs_has_inline_data(inode)) {
+		if (whence == SEEK_HOLE) {
+			data_ofs = isize;
+			goto found;
+		} else if (whence == SEEK_DATA) {
+			data_ofs = offset;
+			goto found;
+		}
 	}
 
 	pgofs = (pgoff_t)(offset >> PAGE_SHIFT);
-- 
2.26.2