4.19-stable review patch. If anyone has any objections, please let me know.
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From: Weichen Chen weichen.chen@mediatek.com
[ Upstream commit d49270a04623ce3c0afddbf3e984cb245aa48e9c ]
When the number of cpu cores is adjusted to 7 or other odd numbers, the zone size will become an odd number. The address of the zone will become: addr of zone0 = BASE addr of zone1 = BASE + zone_size addr of zone2 = BASE + zone_size*2 ... The address of zone1/3/5/7 will be mapped to non-alignment va. Eventually crashes will occur when accessing these va.
So, use ALIGN_DOWN() to make sure the zone size is even to avoid this bug.
Signed-off-by: Weichen Chen weichen.chen@mediatek.com Reviewed-by: Matthias Brugger matthias.bgg@gmail.com Tested-by: "Guilherme G. Piccoli" gpiccoli@igalia.com Link: https://lore.kernel.org/r/20230224023632.6840-1-weichen.chen@mediatek.com Signed-off-by: Kees Cook keescook@chromium.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/pstore/ram.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 33294dee7d7f..0050aa56b0fa 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -590,6 +590,7 @@ static int ramoops_init_przs(const char *name, }
zone_sz = mem_sz / *cnt; + zone_sz = ALIGN_DOWN(zone_sz, 2); if (!zone_sz) { dev_err(dev, "%s zone size == 0\n", name); goto fail;