| Message ID | 20221114021420.4060601-1-senozhatsky@chromium.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | zram: explicitly limit prio_max for static analyzers | expand |
On Mon, 14 Nov 2022 11:14:20 +0900 Sergey Senozhatsky <senozhatsky@chromium.org> wrote: > Reported-by: coverity-bot <keescook+coverity-bot@chromium.org> > Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> > --- > drivers/block/zram/zram_drv.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > index 9d33801e8ba8..e67a124f2e88 100644 > --- a/drivers/block/zram/zram_drv.c > +++ b/drivers/block/zram/zram_drv.c > @@ -1706,6 +1706,7 @@ static int zram_recompress(struct zram *zram, u32 index, struct page *page, > * Iterate the secondary comp algorithms list (in order of priority) > * and try to recompress the page. > */ > + prio_max = min(prio_max, ZRAM_MAX_COMPS); > for (; prio < prio_max; prio++) { > if (!zram->comps[prio]) > continue; I'll queue this as a fix to "zram: introduce recompress sysfs knob". What's it do? A little changelog would be nice, or at least a link to the coverity report?
On (22/11/14 16:41), Andrew Morton wrote: > > drivers/block/zram/zram_drv.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > > index 9d33801e8ba8..e67a124f2e88 100644 > > --- a/drivers/block/zram/zram_drv.c > > +++ b/drivers/block/zram/zram_drv.c > > @@ -1706,6 +1706,7 @@ static int zram_recompress(struct zram *zram, u32 index, struct page *page, > > * Iterate the secondary comp algorithms list (in order of priority) > > * and try to recompress the page. > > */ > > + prio_max = min(prio_max, ZRAM_MAX_COMPS); > > for (; prio < prio_max; prio++) { > > if (!zram->comps[prio]) > > continue; > > I'll queue this as a fix to "zram: introduce recompress sysfs knob". > > What's it do? A little changelog would be nice, or at least a link to > the coverity report? It doesn't do much, coverity (static analyzer?) got confused by the code, so this simply is supposed to help coverity figure out that we never do an out of bounds access in comps[] array: https://lore.kernel.org/lkml/202211100847.388C61B3@keescook/
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 9d33801e8ba8..e67a124f2e88 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1706,6 +1706,7 @@ static int zram_recompress(struct zram *zram, u32 index, struct page *page, * Iterate the secondary comp algorithms list (in order of priority) * and try to recompress the page. */ + prio_max = min(prio_max, ZRAM_MAX_COMPS); for (; prio < prio_max; prio++) { if (!zram->comps[prio]) continue;
Reported-by: coverity-bot <keescook+coverity-bot@chromium.org> Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> --- drivers/block/zram/zram_drv.c | 1 + 1 file changed, 1 insertion(+)