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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	alan@lxorguk.ukuu.org.uk, Denis Kirjanov <kirjanov@gmail.com>,
	Doug Thompson <dougthompson@xmission.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Borislav Petkov <borislav.petkov@amd.com>
Subject: [ 16/31] amd64_edac:__amd64_set_scrub_rate(): avoid overindexing scrubrates[]
Date: Thu, 25 Oct 2012 17:04:23 -0700	[thread overview]
Message-ID: <20121026000216.604656055@linuxfoundation.org> (raw)
In-Reply-To: <20121026000214.941721299@linuxfoundation.org>

3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andrew Morton <akpm@linux-foundation.org>

commit 168bfeef7bba3f9784f7540b053e4ac72b769ce9 upstream.

If none of the elements in scrubrates[] matches, this loop will cause
__amd64_set_scrub_rate() to incorrectly use the n+1th element.

As the function is designed to use the final scrubrates[] element in the
case of no match, we can fix this bug by simply terminating the array
search at the n-1th element.

Boris: this code is fragile anyway, see here why:
http://marc.info/?l=linux-kernel&m=135102834131236&w=2

It will be rewritten more robustly soonish.

Reported-by: Denis Kirjanov <kirjanov@gmail.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/edac/amd64_edac.c |   11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -161,8 +161,11 @@ static int __amd64_set_scrub_rate(struct
 	 * memory controller and apply to register. Search for the first
 	 * bandwidth entry that is greater or equal than the setting requested
 	 * and program that. If at last entry, turn off DRAM scrubbing.
+	 *
+	 * If no suitable bandwidth is found, turn off DRAM scrubbing entirely
+	 * by falling back to the last element in scrubrates[].
 	 */
-	for (i = 0; i < ARRAY_SIZE(scrubrates); i++) {
+	for (i = 0; i < ARRAY_SIZE(scrubrates) - 1; i++) {
 		/*
 		 * skip scrub rates which aren't recommended
 		 * (see F10 BKDG, F3x58)
@@ -172,12 +175,6 @@ static int __amd64_set_scrub_rate(struct
 
 		if (scrubrates[i].bandwidth <= new_bw)
 			break;
-
-		/*
-		 * if no suitable bandwidth found, turn off DRAM scrubbing
-		 * entirely by falling back to the last element in the
-		 * scrubrates array.
-		 */
 	}
 
 	scrubval = scrubrates[i].scrubval;



  parent reply	other threads:[~2012-10-26  0:04 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-26  0:04 [ 00/31] 3.0.49-stable review Greg Kroah-Hartman
2012-10-26  0:04 ` [ 01/31] arch/tile: avoid generating .eh_frame information in modules Greg Kroah-Hartman
2012-10-26  0:04 ` [ 02/31] NLM: nlm_lookup_file() may return NLMv4-specific error codes Greg Kroah-Hartman
2012-10-26  0:04 ` [ 03/31] oprofile, x86: Fix wrapping bug in op_x86_get_ctrl() Greg Kroah-Hartman
2012-10-26  0:04 ` [ 04/31] SUNRPC: Prevent kernel stack corruption on long values of flush Greg Kroah-Hartman
2012-10-26  0:04 ` [ 05/31] Revert: lockd: use rpc clients cl_nodename for id encoding Greg Kroah-Hartman
2012-10-26  0:04 ` [ 06/31] pcmcia: sharpsl: dont discard sharpsl_pcmcia_ops Greg Kroah-Hartman
2012-10-26  0:04 ` [ 07/31] kernel/sys.c: fix stack memory content leak via UNAME26 Greg Kroah-Hartman
2012-10-26  0:04 ` [ 09/31] x86: Exclude E820_RESERVED regions and memory holes above 4 GB from direct mapping Greg Kroah-Hartman
2012-10-26  0:04 ` [ 10/31] xen/x86: dont corrupt %eip when returning from a signal handler Greg Kroah-Hartman
2012-10-26  0:04 ` [ 11/31] USB: cdc-acm: fix pipe type of write endpoint Greg Kroah-Hartman
2012-10-26  0:04 ` [ 12/31] usb: acm: fix the computation of the number of data bits Greg Kroah-Hartman
2012-10-26  0:04 ` [ 13/31] USB: option: blacklist net interface on ZTE devices Greg Kroah-Hartman
2012-10-26  0:04 ` [ 14/31] USB: option: add more " Greg Kroah-Hartman
2012-10-26  0:04 ` [ 15/31] cgroup: notify_on_release may not be triggered in some cases Greg Kroah-Hartman
2012-10-26  0:04 ` Greg Kroah-Hartman [this message]
2012-10-26  0:04 ` [ 17/31] media: au0828: fix case where STREAMOFF being called on stopped stream causes BUG() Greg Kroah-Hartman
2012-10-26  0:04 ` [ 18/31] drm/i915: apply timing generator bug workaround on CPT and PPT Greg Kroah-Hartman
2012-10-26  0:04 ` [ 19/31] net: Fix skb_under_panic oops in neigh_resolve_output Greg Kroah-Hartman
2012-10-26  0:04 ` [ 20/31] skge: Add DMA mask quirk for Marvell 88E8001 on ASUS P5NSLI motherboard Greg Kroah-Hartman
2012-10-26  0:04 ` [ 21/31] RDS: fix rds-ping spinlock recursion Greg Kroah-Hartman
2012-10-26  0:04 ` [ 22/31] tcp: resets are misrouted Greg Kroah-Hartman
2012-10-26  0:04 ` [ 23/31] sparc64: fix ptrace interaction with force_successful_syscall_return() Greg Kroah-Hartman
2012-10-26  0:04 ` [ 24/31] sparc64: Like x86 we should check current->mm during perf backtrace generation Greg Kroah-Hartman
2012-10-26  0:04 ` [ 25/31] sparc64: Fix bit twiddling in sparc_pmu_enable_event() Greg Kroah-Hartman
2012-10-26  0:04 ` [ 26/31] sparc64: do not clobber personality flags in sys_sparc64_personality() Greg Kroah-Hartman
2012-10-26  0:04 ` [ 27/31] sparc64: Be less verbose during vmemmap population Greg Kroah-Hartman
2012-10-26  0:04 ` [ 28/31] xHCI: add cmd_ring_state Greg Kroah-Hartman
2012-10-26  0:04 ` [ 29/31] xHCI: add aborting command ring function Greg Kroah-Hartman
2012-10-26  0:04 ` [ 30/31] xHCI: cancel command after command timeout Greg Kroah-Hartman
2012-10-26  0:04 ` [ 31/31] xHCI: handle command after aborting the command ring Greg Kroah-Hartman

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