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| author |   Andrew Morton <akpm@linux-foundation.org> | 2012-10-23 14:09:39 -0700 |
|---|---|---|
| committer |   Borislav Petkov <borislav.petkov@amd.com> | 2012-10-24 16:13:27 +0200 |
| commit | 168bfeef7bba3f9784f7540b053e4ac72b769ce9 (patch) | |
| tree | a02890616eb3d65377be628ff9cd1b577beb36df /drivers/edac/amd64_edac.c | |
| parent | Linux 3.7-rc2 (diff) | |
| download | linux-dev-168bfeef7bba3f9784f7540b053e4ac72b769ce9.tar.xz linux-dev-168bfeef7bba3f9784f7540b053e4ac72b769ce9.zip | |
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>
Diffstat (limited to 'drivers/edac/amd64_edac.c')
| -rw-r--r-- | drivers/edac/amd64_edac.c | 11 |
1 files 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; |