Messages in this thread Patch in this message | | | Date | Wed, 24 Oct 2012 16:44:11 +0200 | From | Borislav Petkov <> | Subject | [GIT PULL] amd64_edac fix for 3.7-rc3 |
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Hi Linus,
please pull this fix for when setting the memory controller scrub rate in amd64_edac.
Thanks.
The following changes since commit 6f0c0580b70c89094b3422ba81118c7b959c7556:
Linux 3.7-rc2 (2012-10-20 12:11:32 -0700)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp.git tags/edac_scrubrates_fix
for you to fetch changes up to 168bfeef7bba3f9784f7540b053e4ac72b769ce9:
amd64_edac:__amd64_set_scrub_rate(): avoid overindexing scrubrates[] (2012-10-24 16:13:27 +0200)
---------------------------------------------------------------- An array out-of-bounds fix from Andrew when setting the scrub rate of the memory controller.
---------------------------------------------------------------- Andrew Morton (1): amd64_edac:__amd64_set_scrub_rate(): avoid overindexing scrubrates[]
drivers/edac/amd64_edac.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)
Actual patch:
-- From 168bfeef7bba3f9784f7540b053e4ac72b769ce9 Mon Sep 17 00:00:00 2001 From: Andrew Morton <akpm@linux-foundation.org> Date: Tue, 23 Oct 2012 14:09:39 -0700 Subject: [PATCH] amd64_edac:__amd64_set_scrub_rate(): avoid overindexing scrubrates[]
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: stable@vger.kernel.org Cc: Doug Thompson <dougthompson@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com> --- drivers/edac/amd64_edac.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c index 5a297a26211d..cc8e7c78a23c 100644 --- a/drivers/edac/amd64_edac.c +++ b/drivers/edac/amd64_edac.c @@ -170,8 +170,11 @@ static int __amd64_set_scrub_rate(struct pci_dev *ctl, u32 new_bw, u32 min_rate) * 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) @@ -181,12 +184,6 @@ static int __amd64_set_scrub_rate(struct pci_dev *ctl, u32 new_bw, u32 min_rate) 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; -- 1.8.0
-- Regards/Gruss, Boris.
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