6e98b3ce31
- Fix a potential race condition when checking uinput device's syspath (inactive in Fedora, we use the ioctl and never get here)
50 lines
1.4 KiB
Diff
50 lines
1.4 KiB
Diff
From 1c3a79543488399081a00f9405d5c64af62aa6c5 Mon Sep 17 00:00:00 2001
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From: Peter Hutterer <peter.hutterer@who-t.net>
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Date: Tue, 22 Dec 2015 09:02:46 +1000
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Subject: [PATCH libevdev 3/3] uinput: fix race condition in uinput syspath
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check
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In theory, the device could change between stat() call and open(), resulting
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in us opening the new device. Change to open() first, then fstat() on the fd.
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Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
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---
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libevdev/libevdev-uinput.c | 16 ++++++++--------
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1 file changed, 8 insertions(+), 8 deletions(-)
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diff --git a/libevdev/libevdev-uinput.c b/libevdev/libevdev-uinput.c
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index ba323ed..24e049f 100644
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--- a/libevdev/libevdev-uinput.c
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+++ b/libevdev/libevdev-uinput.c
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@@ -225,19 +225,19 @@ fetch_syspath_and_devnode(struct libevdev_uinput *uinput_dev)
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continue;
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}
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- if (stat(buf, &st) == -1)
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- continue;
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-
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- /* created before UI_DEV_CREATE, or after it finished */
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- if (st.st_ctime < uinput_dev->ctime[0] ||
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- st.st_ctime > uinput_dev->ctime[1])
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- continue;
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-
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/* created within time frame */
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fd = open(buf, O_RDONLY);
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if (fd < 0)
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continue;
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+ /* created before UI_DEV_CREATE, or after it finished */
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+ if (fstat(fd, &st) == -1 ||
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+ st.st_ctime < uinput_dev->ctime[0] ||
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+ st.st_ctime > uinput_dev->ctime[1]) {
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+ close(fd);
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+ continue;
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+ }
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+
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len = read(fd, buf, sizeof(buf));
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close(fd);
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if (len <= 0)
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--
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2.5.0
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