diff options
| author | David Disseldorp <ddiss@suse.de> | 2021-07-21 00:55:22 +0200 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2021-07-20 23:18:22 -0400 |
| commit | a47fa41381a09e5997afd762664db4f5f6657e03 (patch) | |
| tree | ae8bb707ec8c8a89fbb6d31e4faed343c3b4a6fa /drivers/target | |
| parent | fae21608c31ca987d9dfc0422ac9b5bd21c213a6 (diff) | |
| download | lwn-a47fa41381a09e5997afd762664db4f5f6657e03.tar.gz lwn-a47fa41381a09e5997afd762664db4f5f6657e03.zip | |
scsi: target: Fix NULL dereference on XCOPY completion
CPU affinity control added with commit 39ae3edda325 ("scsi: target: core:
Make completion affinity configurable") makes target_complete_cmd() queue
work on a CPU based on se_tpg->se_tpg_wwn->cmd_compl_affinity state.
LIO's EXTENDED COPY worker is a special case in that read/write cmds are
dispatched using the global xcopy_pt_tpg, which carries a NULL se_tpg_wwn
pointer following initialization in target_xcopy_setup_pt().
The NULL xcopy_pt_tpg->se_tpg_wwn pointer is dereferenced on completion of
any EXTENDED COPY initiated read/write cmds. E.g using the libiscsi
SCSI.ExtendedCopy.Simple test:
BUG: kernel NULL pointer dereference, address: 00000000000001a8
RIP: 0010:target_complete_cmd+0x9d/0x130 [target_core_mod]
Call Trace:
fd_execute_rw+0x148/0x42a [target_core_file]
? __dynamic_pr_debug+0xa7/0xe0
? target_check_reservation+0x5b/0x940 [target_core_mod]
__target_execute_cmd+0x1e/0x90 [target_core_mod]
transport_generic_new_cmd+0x17c/0x330 [target_core_mod]
target_xcopy_issue_pt_cmd+0x9/0x60 [target_core_mod]
target_xcopy_read_source.isra.7+0x10b/0x1b0 [target_core_mod]
? target_check_fua+0x40/0x40 [target_core_mod]
? transport_complete_task_attr+0x130/0x130 [target_core_mod]
target_xcopy_do_work+0x61f/0xc00 [target_core_mod]
This fix makes target_complete_cmd() queue work on se_cmd->cpuid if
se_tpg_wwn is NULL.
Link: https://lore.kernel.org/r/20210720225522.26291-1-ddiss@suse.de
Fixes: 39ae3edda325 ("scsi: target: core: Make completion affinity configurable")
Cc: Lee Duncan <lduncan@suse.com>
Cc: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/target')
| -rw-r--r-- | drivers/target/target_core_transport.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 7e35eddd9eb7..26ceabe34de5 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -886,7 +886,7 @@ void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status) INIT_WORK(&cmd->work, success ? target_complete_ok_work : target_complete_failure_work); - if (wwn->cmd_compl_affinity == SE_COMPL_AFFINITY_CPUID) + if (!wwn || wwn->cmd_compl_affinity == SE_COMPL_AFFINITY_CPUID) cpu = cmd->cpuid; else cpu = wwn->cmd_compl_affinity; |