forked from pool/xorg-x11-server
Stefan Dirsch
37722e6dc6
* XkbGetKbdByName use-after-free (ZDI-CAN-19530, CVE-2022-4283,
bsc#1206017)
- U_0001-Xtest-disallow-GenericEvents-in-XTestSwapFakeInput.patch
* Server XTestSwapFakeInput stack overflow (ZDI-CAN 19265,
CVE-2022-46340, bsc#1205874)
- U_0002-Xi-return-an-error-from-XI-property-changes-if-verif.patch
* Xi: return an error from XI property changes if verification
failed (no ZDI-CAN id, no CVE id, bsc#1205875)
- U_0003-Xi-avoid-integer-truncation-in-length-check-of-ProcX.patch
* Server XIChangeProperty out-of-bounds access (ZDI-CAN 19405,
CVE-2022-46344, bsc#1205876)
- U_0004-Xi-disallow-passive-grabs-with-a-detail-255.patch
* Server XIPassiveUngrabDevice out-of-bounds access (ZDI-CAN 19381,
CVE-2022-46341, bsc#1205877)
- U_0005-Xext-free-the-screen-saver-resource-when-replacing-i.patch
* Server ScreenSaverSetAttributes use-after-free (ZDI-CAN 19404,
CVE-2022-46343, bsc#1205878)
- U_0006-Xext-free-the-XvRTVideoNotify-when-turning-off-from-.patch
* Server XvdiSelectVideoNotify use-after-free (ZDI-CAN 19400,
CVE-2022-46342, bsc#1205879)
OBS-URL: https://build.opensuse.org/package/show/X11:XOrg/xorg-x11-server?expand=0&rev=843
74 lines
2.9 KiB
Diff
74 lines
2.9 KiB
Diff
From 4ca304326d3b222a446aca82ec3c28ee8adf8446 Mon Sep 17 00:00:00 2001
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From: Peter Hutterer <peter.hutterer@who-t.net>
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Date: Wed, 30 Nov 2022 11:20:40 +1000
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Subject: [PATCH xserver 6/6] Xext: free the XvRTVideoNotify when turning off
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from the same client
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This fixes a use-after-free bug:
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When a client first calls XvdiSelectVideoNotify() on a drawable with a
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TRUE onoff argument, a struct XvVideoNotifyRec is allocated. This struct
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is added twice to the resources:
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- as the drawable's XvRTVideoNotifyList. This happens only once per
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drawable, subsequent calls append to this list.
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- as the client's XvRTVideoNotify. This happens for every client.
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The struct keeps the ClientPtr around once it has been added for a
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client. The idea, presumably, is that if the client disconnects we can remove
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all structs from the drawable's list that match the client (by resetting
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the ClientPtr to NULL), but if the drawable is destroyed we can remove
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and free the whole list.
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However, if the same client then calls XvdiSelectVideoNotify() on the
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same drawable with a FALSE onoff argument, only the ClientPtr on the
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existing struct was set to NULL. The struct itself remained in the
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client's resources.
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If the drawable is now destroyed, the resource system invokes
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XvdiDestroyVideoNotifyList which frees the whole list for this drawable
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- including our struct. This function however does not free the resource
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for the client since our ClientPtr is NULL.
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Later, when the client is destroyed and the resource system invokes
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XvdiDestroyVideoNotify, we unconditionally set the ClientPtr to NULL. On
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a struct that has been freed previously. This is generally frowned upon.
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Fix this by calling FreeResource() on the second call instead of merely
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setting the ClientPtr to NULL. This removes the struct from the client
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resources (but not from the list), ensuring that it won't be accessed
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again when the client quits.
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Note that the assignment tpn->client = NULL; is superfluous since the
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XvdiDestroyVideoNotify function will do this anyway. But it's left for
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clarity and to match a similar invocation in XvdiSelectPortNotify.
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ZDI-CAN 19400
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This vulnerability was discovered by:
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Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
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Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
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---
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Xext/xvmain.c | 4 +++-
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1 file changed, 3 insertions(+), 1 deletion(-)
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diff --git a/Xext/xvmain.c b/Xext/xvmain.c
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index f627471938..2a08f8744a 100644
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--- a/Xext/xvmain.c
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+++ b/Xext/xvmain.c
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@@ -811,8 +811,10 @@ XvdiSelectVideoNotify(ClientPtr client, DrawablePtr pDraw, BOOL onoff)
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tpn = pn;
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while (tpn) {
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if (tpn->client == client) {
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- if (!onoff)
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+ if (!onoff) {
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tpn->client = NULL;
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+ FreeResource(tpn->id, XvRTVideoNotify);
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+ }
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return Success;
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}
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if (!tpn->client)
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--
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2.38.1
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