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authorGuilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>2017-11-17 19:14:55 -0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-02-03 17:05:40 +0100
commitfa64914313c1437c7ba843581a0b09bc2870bec3 (patch)
treeb286574fdb325c9c92ec3144a585ba2692c79897 /drivers/scsi
parentfde77c712ac003f023ea6ba3da30a0284c71ad92 (diff)
scsi: aacraid: Prevent crash in case of free interrupt during scsi EH path
[ Upstream commit e4717292ddebcfe231651b5aff9fa19ca158d178 ] 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> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/aacraid/commsup.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/scsi/aacraid/commsup.c b/drivers/scsi/aacraid/commsup.c
index 0aeecec1f5ea..e2962f15c189 100644
--- a/drivers/scsi/aacraid/commsup.c
+++ b/drivers/scsi/aacraid/commsup.c
@@ -1416,13 +1416,13 @@ static int _aac_reset_adapter(struct aac_dev *aac, int forced)
* will ensure that i/o is queisced and the card is flushed in that
* case.
*/
+ aac_free_irq(aac);
aac_fib_map_free(aac);
pci_free_consistent(aac->pdev, aac->comm_size, aac->comm_addr, aac->comm_phys);
aac->comm_addr = NULL;
aac->comm_phys = 0;
kfree(aac->queues);
aac->queues = NULL;
- aac_free_irq(aac);
kfree(aac->fsa_dev);
aac->fsa_dev = NULL;
quirks = aac_get_driver_ident(index)->quirks;