From: Yun Hsiang <yun.hsiang@mediatek.com> To: Matthias Brugger <matthias.bgg@gmail.com>, Peter Zijlstra <peterz@infradead.org> Cc: Yun Hsiang <yun.hsiang@mediatek.com>, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, wsd_upstream@mediatek.com Subject: [PATCH 1/1] psi: fix underflow in psi_write Date: Mon, 18 Nov 2019 11:12:42 +0800 [thread overview] Message-ID: <1574046762-26418-1-git-send-email-yun.hsiang@mediatek.com> (raw) There is a stack-out-of-bounds write when running syzkaller test. psi_write will perform a underflow write if nbytes received 0. Fix this behavior by return -EINVAL when nbytes == 0. Here is the KASAN log. ================================================================== BUG: KASAN: stack-out-of-bounds in psi_write.part.9+0x128/0x270 Write of size 1 at addr ffffffc0e601fb7f by task syz-executor4/25565 CPU: 7 PID: 25565 Comm: syz-executor4 Tainted: G S W O 4.14.141+ #1 Call trace: [<ffffff90080969e0>] dump_backtrace+0x0/0x828 [<ffffff9008097228>] show_stack+0x20/0x30 [<ffffff9009c5a040>] dump_stack+0xd0/0x120 [<ffffff9008411818>] print_address_description+0x68/0x4d0 [<ffffff9008411fa0>] kasan_report+0x1a0/0x3e8 [<ffffff900840fd14>] __asan_store1+0x4c/0x58 [<ffffff90081b44b0>] psi_write.part.9+0x128/0x270 [<ffffff90081b4660>] psi_memory_write+0x30/0x38 [<ffffff900852a220>] proc_reg_write+0xb8/0x108 [<ffffff900843e78c>] __vfs_write+0xdc/0x2d8 [<ffffff900843ec50>] vfs_write+0xe8/0x278 [<ffffff900843f150>] SyS_write+0xd0/0x1a8 Signed-off-by: Yun Hsiang <yun.hsiang@mediatek.com> --- kernel/sched/psi.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 6e52b67..ce89894 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -1199,6 +1199,9 @@ static ssize_t psi_write(struct file *file, const char __user *user_buf, return -EOPNOTSUPP; buf_size = min(nbytes, (sizeof(buf) - 1)); + if (buf_size == 0) + return -EINVAL; + if (copy_from_user(buf, user_buf, buf_size)) return -EFAULT; -- 1.7.9.5 _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek
WARNING: multiple messages have this Message-ID (diff)
From: Yun Hsiang <yun.hsiang@mediatek.com> To: Matthias Brugger <matthias.bgg@gmail.com>, Peter Zijlstra <peterz@infradead.org> Cc: Yun Hsiang <yun.hsiang@mediatek.com>, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, wsd_upstream@mediatek.com Subject: [PATCH 1/1] psi: fix underflow in psi_write Date: Mon, 18 Nov 2019 11:12:42 +0800 [thread overview] Message-ID: <1574046762-26418-1-git-send-email-yun.hsiang@mediatek.com> (raw) There is a stack-out-of-bounds write when running syzkaller test. psi_write will perform a underflow write if nbytes received 0. Fix this behavior by return -EINVAL when nbytes == 0. Here is the KASAN log. ================================================================== BUG: KASAN: stack-out-of-bounds in psi_write.part.9+0x128/0x270 Write of size 1 at addr ffffffc0e601fb7f by task syz-executor4/25565 CPU: 7 PID: 25565 Comm: syz-executor4 Tainted: G S W O 4.14.141+ #1 Call trace: [<ffffff90080969e0>] dump_backtrace+0x0/0x828 [<ffffff9008097228>] show_stack+0x20/0x30 [<ffffff9009c5a040>] dump_stack+0xd0/0x120 [<ffffff9008411818>] print_address_description+0x68/0x4d0 [<ffffff9008411fa0>] kasan_report+0x1a0/0x3e8 [<ffffff900840fd14>] __asan_store1+0x4c/0x58 [<ffffff90081b44b0>] psi_write.part.9+0x128/0x270 [<ffffff90081b4660>] psi_memory_write+0x30/0x38 [<ffffff900852a220>] proc_reg_write+0xb8/0x108 [<ffffff900843e78c>] __vfs_write+0xdc/0x2d8 [<ffffff900843ec50>] vfs_write+0xe8/0x278 [<ffffff900843f150>] SyS_write+0xd0/0x1a8 Signed-off-by: Yun Hsiang <yun.hsiang@mediatek.com> --- kernel/sched/psi.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c index 6e52b67..ce89894 100644 --- a/kernel/sched/psi.c +++ b/kernel/sched/psi.c @@ -1199,6 +1199,9 @@ static ssize_t psi_write(struct file *file, const char __user *user_buf, return -EOPNOTSUPP; buf_size = min(nbytes, (sizeof(buf) - 1)); + if (buf_size == 0) + return -EINVAL; + if (copy_from_user(buf, user_buf, buf_size)) return -EFAULT; -- 1.7.9.5 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2019-11-18 3:13 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-18 3:12 Yun Hsiang [this message] 2019-11-18 3:12 ` [PATCH 1/1] psi: fix underflow in psi_write Yun Hsiang
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