Commit f1601113 authored Nov 02, 2017 by Rameshwar Prasad Sahu Committed by Tejun Heo Nov 03, 2017

ata: fixes kernel crash while tracing ata_eh_link_autopsy event



When tracing ata link error event, the kernel crashes when the disk is
removed due to NULL pointer access by trace_ata_eh_link_autopsy API.
This occurs as the dev is NULL when the disk disappeared. This patch
fixes this crash by calling trace_ata_eh_link_autopsy only if "dev"
is not NULL.

v2 changes:
 Removed direct passing "link" pointer instead of "dev" in trace API.

Signed-off-by: Rameshwar Prasad Sahu <rsahu@apm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 255c03d1 ("libata: Add tracepoints")
Cc: stable@vger.kernel.org # v4.1+

parent e00b19e2

drivers/ata/libata-eh.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2264,8 +2264,8 @@ static void ata_eh_link_autopsy(struct ata_link *link)
		if (dev->flags & ATA_DFLAG_DUBIOUS_XFER)
		eflags \|= ATA_EFLAG_DUBIOUS_XFER;
		ehc->i.action \|= ata_eh_speed_down(dev, eflags, all_err_mask);
		}
		trace_ata_eh_link_autopsy(dev, ehc->i.action, all_err_mask);
		}
		DPRINTK("EXIT\n");
		}

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