@@ -793,6 +793,13 @@ int f2fs_write_inode(struct inode *inode, struct writeback_control *wbc)
!is_inode_flag_set(inode, FI_DIRTY_INODE))
return 0;
+ /*
+ * no need to update inode page, ultimately f2fs_evict_inode() will
+ * clear dirty status of inode.
+ */
+ if (f2fs_cp_error(sbi))
+ return -EIO;
+
if (!f2fs_is_checkpoint_ready(sbi)) {
f2fs_mark_inode_dirty_sync(inode, true);
return -ENOSPC;
@@ -559,13 +559,16 @@ static inline bool has_curseg_enough_space(struct f2fs_sb_info *sbi,
unsigned int node_blocks, unsigned int data_blocks,
unsigned int dent_blocks)
{
-
unsigned int segno, left_blocks, blocks;
int i;
/* check current data/node sections in the worst case. */
for (i = CURSEG_HOT_DATA; i < NR_PERSISTENT_LOG; i++) {
segno = CURSEG_I(sbi, i)->segno;
+
+ if (unlikely(segno == NULL_SEGNO))
+ return false;
+
left_blocks = CAP_BLKS_PER_SEC(sbi) -
get_ckpt_valid_blocks(sbi, segno, true);
@@ -576,6 +579,10 @@ static inline bool has_curseg_enough_space(struct f2fs_sb_info *sbi,
/* check current data section for dentry blocks. */
segno = CURSEG_I(sbi, CURSEG_HOT_DATA)->segno;
+
+ if (unlikely(segno == NULL_SEGNO))
+ return false;
+
left_blocks = CAP_BLKS_PER_SEC(sbi) -
get_ckpt_valid_blocks(sbi, segno, true);
if (dent_blocks > left_blocks)
syzbot reports a f2fs bug as below: F2FS-fs (loop3): Stopped filesystem due to reason: 7 kworker/u8:7: attempt to access beyond end of device BUG: unable to handle page fault for address: ffffed1604ea3dfa RIP: 0010:get_ckpt_valid_blocks fs/f2fs/segment.h:361 [inline] RIP: 0010:has_curseg_enough_space fs/f2fs/segment.h:570 [inline] RIP: 0010:__get_secs_required fs/f2fs/segment.h:620 [inline] RIP: 0010:has_not_enough_free_secs fs/f2fs/segment.h:633 [inline] RIP: 0010:has_enough_free_secs+0x575/0x1660 fs/f2fs/segment.h:649 <TASK> f2fs_is_checkpoint_ready fs/f2fs/segment.h:671 [inline] f2fs_write_inode+0x425/0x540 fs/f2fs/inode.c:791 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x708/0x10d0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 wb_writeback+0x413/0xb80 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x410/0x1080 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Commit 8b10d3653735 ("f2fs: introduce FAULT_NO_SEGMENT") allows to trigger no free segment fault in allocator, then it will update curseg->segno to NULL_SEGNO, though, CP_ERROR_FLAG has been set, f2fs_write_inode() missed to check the flag, and access invalid curseg->segno directly in below call path, then resulting in panic: - f2fs_write_inode - f2fs_is_checkpoint_ready - has_enough_free_secs - has_not_enough_free_secs - __get_secs_required - has_curseg_enough_space - get_ckpt_valid_blocks : access invalid curseg->segno To avoid this issue, let's: - check CP_ERROR_FLAG flag in prior to f2fs_is_checkpoint_ready() in f2fs_write_inode(). - in has_curseg_enough_space(), save curseg->segno into a temp variable, and verify its validation before use. Fixes: 8b10d3653735 ("f2fs: introduce FAULT_NO_SEGMENT") Reported-by: syzbot+b6b347b7a4ea1b2e29b6@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67973c2b.050a0220.11b1bb.0089.GAE@google.com Signed-off-by: Chao Yu <chao@kernel.org> --- v2: - get rid of potential blocking on curseg_mutex fs/f2fs/inode.c | 7 +++++++ fs/f2fs/segment.h | 9 ++++++++- 2 files changed, 15 insertions(+), 1 deletion(-)