* [PATCH AUTOSEL 4.19 07/12] pstore/ram: Fix crash when setting number of cpus to an odd number
[not found] <20240116002817.216837-1-sashal@kernel.org>
@ 2024-01-16 0:28 ` Sasha Levin
0 siblings, 0 replies; only message in thread
From: Sasha Levin @ 2024-01-16 0:28 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Weichen Chen, Matthias Brugger, Guilherme G. Piccoli, Kees Cook,
Sasha Levin, angelogioacchino.delregno, linux-hardening,
linux-arm-kernel, linux-mediatek
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;
--
2.43.0
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