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| author |  Chao Yu <yuchao0@huawei.com>
| 2017-01-25 10:52:40 +0800 |
|---|---|---|
| committer |  Jaegeuk Kim <jaegeuk@kernel.org>
| 2017-02-22 20:24:52 -0800 |
| commit | 73545817c90edcb367a65720f669cddce633bc46 (patch) | |
| tree | b0ae79628818f60ff42389991e63278abe9435de /fs/f2fs | |
| parent | f2fs: fix to avoid overflow when left shifting page offset (diff) | |
| download | linux-73545817c90edcb367a65720f669cddce633bc46.tar.gz linux-73545817c90edcb367a65720f669cddce633bc46.tar.bz2 linux-73545817c90edcb367a65720f669cddce633bc46.zip | |
f2fs: fix null pointer dereference when issuing flush in ->fsync
We only allocate flush merge control structure sbi::sm_info::fcc_info when
flush_merge option is on, but in f2fs_issue_flush we still try to access
member of the control structure without that option, it incurs panic as
show below, fix it.
Call Trace:
__remove_ino_entry+0xa9/0xc0 [f2fs]
f2fs_do_sync_file.isra.27+0x214/0x6d0 [f2fs]
f2fs_sync_file+0x18/0x20 [f2fs]
vfs_fsync_range+0x3d/0xb0
__do_page_fault+0x261/0x4d0
do_fsync+0x3d/0x70
SyS_fsync+0x10/0x20
do_syscall_64+0x6e/0x180
entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x7f18ce260de0
RSP: 002b:00007ffdd4589258 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f18ce260de0
RDX: 0000000000000006 RSI: 00000000016c0360 RDI: 0000000000000003
RBP: 00000000016c0360 R08: 000000000000ffff R09: 000000000000001f
R10: 00007ffdd4589020 R11: 0000000000000246 R12: 00000000016c0100
R13: 0000000000000000 R14: 00000000016c1f00 R15: 00000000016c0100
Code: fb 81 e3 00 08 00 00 48 89 45 a0 0f 1f 44 00 00 31 c0 85 db 75 27 41 81 e7 00 04 00 00 74 0c 41 8b 45 20 85 c0 0f 85 81 00 00 00 <f0> 41 ff 45 20 4c 89 e7 e8 f8 e9 ff ff f0 41 ff 4d 20 48 83 c4
RIP: f2fs_issue_flush+0x5b/0x170 [f2fs] RSP: ffffc90003b5fd78
CR2: 0000000000000020
---[ end trace a09314c24f037648 ]---
Reported-by: Shuoran Liu <liushuoran@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
| -rw-r--r-- | fs/f2fs/segment.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 52b133725b7f..4e515bbbeddc 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -477,7 +477,10 @@ int f2fs_issue_flush(struct f2fs_sb_info *sbi) if (test_opt(sbi, NOBARRIER)) return 0; - if (!test_opt(sbi, FLUSH_MERGE) || !atomic_read(&fcc->submit_flush)) { + if (!test_opt(sbi, FLUSH_MERGE)) + return submit_flush_wait(sbi); + + if (!atomic_read(&fcc->submit_flush)) { int ret; atomic_inc(&fcc->submit_flush); |