diff options
| author | Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> | 2017-11-17 19:14:55 -0200 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2017-11-20 22:33:09 -0500 |
| commit | e4717292ddebcfe231651b5aff9fa19ca158d178 (patch) | |
| tree | dc7cdf6388307b510c1b7dea023967a3d5f9cc39 /drivers | |
| parent | d9b6d85a38df398cfe0ba3f0fae59d58c9a6d433 (diff) | |
scsi: aacraid: Prevent crash in case of free interrupt during scsi EH path
As part of the scsi EH path, aacraid performs a reinitialization of the
adapter, which encompass freeing resources and IRQs, NULLifying lots of
pointers, and then initialize it all over again. We've identified a
problem during the free IRQ portion of this path if CONFIG_DEBUG_SHIRQ
is enabled on kernel config file.
Happens that, in case this flag was set, right after free_irq()
effectively clears the interrupt, it checks if it was requested as
IRQF_SHARED. In positive case, it performs another call to the IRQ
handler on driver. Problem is: since aacraid currently free some
resources *before* freeing the IRQ, once free_irq() path calls the
handler again (due to CONFIG_DEBUG_SHIRQ), aacraid crashes due to NULL
pointer dereference with the following trace:
aac_src_intr_message+0xf8/0x740 [aacraid]
__free_irq+0x33c/0x4a0
free_irq+0x78/0xb0
aac_free_irq+0x13c/0x150 [aacraid]
aac_reset_adapter+0x2e8/0x970 [aacraid]
aac_eh_reset+0x3a8/0x5d0 [aacraid]
scsi_try_host_reset+0x74/0x180
scsi_eh_ready_devs+0xc70/0x1510
scsi_error_handler+0x624/0xa20
This patch prevents the crash by changing the order of the
deinitialization in this path of aacraid: first we clear the IRQ, then
we free other resources. No functional change intended.
Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Reviewed-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/scsi/aacraid/commsup.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/scsi/aacraid/commsup.c b/drivers/scsi/aacraid/commsup.c index 2abe8fd83494..bec9f3193f60 100644 --- a/drivers/scsi/aacraid/commsup.c +++ b/drivers/scsi/aacraid/commsup.c @@ -1554,6 +1554,7 @@ static int _aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type) * will ensure that i/o is queisced and the card is flushed in that * case. */ + aac_free_irq(aac); aac_fib_map_free(aac); dma_free_coherent(&aac->pdev->dev, aac->comm_size, aac->comm_addr, aac->comm_phys); @@ -1561,7 +1562,6 @@ static int _aac_reset_adapter(struct aac_dev *aac, int forced, u8 reset_type) aac->comm_phys = 0; kfree(aac->queues); aac->queues = NULL; - aac_free_irq(aac); kfree(aac->fsa_dev); aac->fsa_dev = NULL; |