diff options
| author | Andrew Morton <akpm@linux-foundation.org> | 2012-10-23 14:09:39 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-28 10:02:12 -0700 |
| commit | a322f9a0799883553a0898c7062a944ff64a3056 (patch) | |
| tree | 87863d7901ea1754290b39324e88f65c6b5a185d /drivers | |
| parent | f0c76f5fa97e436cf24cb57a4aeceb7c83835704 (diff) | |
amd64_edac:__amd64_set_scrub_rate(): avoid overindexing scrubrates[]
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>
Diffstat (limited to 'drivers')
| -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 9a8bebcf6b17..feb2d10bba66 100644 --- a/drivers/edac/amd64_edac.c +++ b/drivers/edac/amd64_edac.c @@ -161,8 +161,11 @@ 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) @@ -172,12 +175,6 @@ 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; |