From: "Gustavo A. R. Silva" gustavo@embeddedor.com
[ Upstream commit 98c49f1746ac44ccc164e914b9a44183fad09f51 ]
Currently, there is an out-of-bounds read on array hpetp->hp_dev in the following for loop:
870 for (i = 0; i < hdp->hd_nirqs; i++) 871 hpetp->hp_dev[i].hd_hdwirq = hdp->hd_irq[i];
This is due to the recent change from one-element array to flexible-array member in struct hpets:
104 struct hpets { ... 113 struct hpet_dev hp_dev[]; 114 };
This change affected the total size of the dynamic memory allocation, decreasing it by one time the size of struct hpet_dev.
Fix this by adjusting the allocation size when calling struct_size().
Fixes: 987f028b8637c ("char: hpet: Use flexible-array member") Signed-off-by: Gustavo A. R. Silva gustavo@embeddedor.com Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Acked-by: Eric Biggers ebiggers@kernel.org Link: https://lore.kernel.org/r/20200129022613.GA24281@embeddedor.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/char/hpet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c index aed2c45f7968c..ed3b7dab678db 100644 --- a/drivers/char/hpet.c +++ b/drivers/char/hpet.c @@ -855,7 +855,7 @@ int hpet_alloc(struct hpet_data *hdp) return 0; }
- hpetp = kzalloc(struct_size(hpetp, hp_dev, hdp->hd_nirqs - 1), + hpetp = kzalloc(struct_size(hpetp, hp_dev, hdp->hd_nirqs), GFP_KERNEL);
if (!hpetp)