From: wangyan wangyan122@huawei.com
[ Upstream commit 9f16ca48fc818a17de8be1f75d08e7f4addc4497 ]
I found a NULL pointer dereference in ocfs2_update_inode_fsync_trans(), handle->h_transaction may be NULL in this situation:
ocfs2_file_write_iter ->__generic_file_write_iter ->generic_perform_write ->ocfs2_write_begin ->ocfs2_write_begin_nolock ->ocfs2_write_cluster_by_desc ->ocfs2_write_cluster ->ocfs2_mark_extent_written ->ocfs2_change_extent_flag ->ocfs2_split_extent ->ocfs2_try_to_merge_extent ->ocfs2_extend_rotate_transaction ->ocfs2_extend_trans ->jbd2_journal_restart ->jbd2__journal_restart // handle->h_transaction is NULL here ->handle->h_transaction = NULL; ->start_this_handle /* journal aborted due to storage network disconnection, return error */ ->return -EROFS; /* line 3806 in ocfs2_try_to_merge_extent (), it will ignore ret error. */ ->ret = 0; ->... ->ocfs2_write_end ->ocfs2_write_end_nolock ->ocfs2_update_inode_fsync_trans // NULL pointer dereference ->oi->i_sync_tid = handle->h_transaction->t_tid;
The information of NULL pointer dereference as follows: JBD2: Detected IO errors while flushing file data on dm-11-45 Aborting journal on device dm-11-45. JBD2: Error -5 detected when updating journal superblock for dm-11-45. (dd,22081,3):ocfs2_extend_trans:474 ERROR: status = -30 (dd,22081,3):ocfs2_try_to_merge_extent:3877 ERROR: status = -30 Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 Mem abort info: ESR = 0x96000004 Exception class = DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 Data abort info: ISV = 0, ISS = 0x00000004 CM = 0, WnR = 0 user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000e74e1338 [0000000000000008] pgd=0000000000000000 Internal error: Oops: 96000004 [#1] SMP Process dd (pid: 22081, stack limit = 0x00000000584f35a9) CPU: 3 PID: 22081 Comm: dd Kdump: loaded Hardware name: Huawei TaiShan 2280 V2/BC82AMDD, BIOS 0.98 08/25/2019 pstate: 60400009 (nZCv daif +PAN -UAO) pc : ocfs2_write_end_nolock+0x2b8/0x550 [ocfs2] lr : ocfs2_write_end_nolock+0x2a0/0x550 [ocfs2] sp : ffff0000459fba70 x29: ffff0000459fba70 x28: 0000000000000000 x27: ffff807ccf7f1000 x26: 0000000000000001 x25: ffff807bdff57970 x24: ffff807caf1d4000 x23: ffff807cc79e9000 x22: 0000000000001000 x21: 000000006c6cd000 x20: ffff0000091d9000 x19: ffff807ccb239db0 x18: ffffffffffffffff x17: 000000000000000e x16: 0000000000000007 x15: ffff807c5e15bd78 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000001 x9 : 0000000000000228 x8 : 000000000000000c x7 : 0000000000000fff x6 : ffff807a308ed6b0 x5 : ffff7e01f10967c0 x4 : 0000000000000018 x3 : d0bc661572445600 x2 : 0000000000000000 x1 : 000000001b2e0200 x0 : 0000000000000000 Call trace: ocfs2_write_end_nolock+0x2b8/0x550 [ocfs2] ocfs2_write_end+0x4c/0x80 [ocfs2] generic_perform_write+0x108/0x1a8 __generic_file_write_iter+0x158/0x1c8 ocfs2_file_write_iter+0x668/0x950 [ocfs2] __vfs_write+0x11c/0x190 vfs_write+0xac/0x1c0 ksys_write+0x6c/0xd8 __arm64_sys_write+0x24/0x30 el0_svc_common+0x78/0x130 el0_svc_handler+0x38/0x78 el0_svc+0x8/0xc
To prevent NULL pointer dereference in this situation, we use is_handle_aborted() before using handle->h_transaction->t_tid.
Link: http://lkml.kernel.org/r/03e750ab-9ade-83aa-b000-b9e81e34e539@huawei.com Signed-off-by: Yan Wang wangyan122@huawei.com Reviewed-by: Jun Piao piaojun@huawei.com Cc: Mark Fasheh mark@fasheh.com Cc: Joel Becker jlbec@evilplan.org Cc: Junxiao Bi junxiao.bi@oracle.com Cc: Joseph Qi jiangqi903@gmail.com Cc: Changwei Ge gechangwei@live.cn Cc: Gang He ghe@suse.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ocfs2/journal.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/fs/ocfs2/journal.h b/fs/ocfs2/journal.h index f4cd3c3e9fb70..0a4d2cbf512f8 100644 --- a/fs/ocfs2/journal.h +++ b/fs/ocfs2/journal.h @@ -637,9 +637,11 @@ static inline void ocfs2_update_inode_fsync_trans(handle_t *handle, { struct ocfs2_inode_info *oi = OCFS2_I(inode);
- oi->i_sync_tid = handle->h_transaction->t_tid; - if (datasync) - oi->i_datasync_tid = handle->h_transaction->t_tid; + if (!is_handle_aborted(handle)) { + oi->i_sync_tid = handle->h_transaction->t_tid; + if (datasync) + oi->i_datasync_tid = handle->h_transaction->t_tid; + } }
#endif /* OCFS2_JOURNAL_H */