xserver: Branch 'master' - 7 commits

GitLab Mirror gitlab-mirror at kemper.freedesktop.org
Tue Jun 17 13:17:39 UTC 2025


 dix/dispatch.c                 |    9 +++++----
 hw/xfree86/modes/xf86RandR12.c |    6 ++++--
 os/io.c                        |    6 +++++-
 randr/rrproviderproperty.c     |    3 ++-
 record/record.c                |    8 ++++++++
 render/animcur.c               |    3 +++
 render/render.c                |    2 ++
 xfixes/disconnect.c            |    3 ++-
 8 files changed, 31 insertions(+), 9 deletions(-)

New commits:
commit 0235121c6a7a6eb247e2addb3b41ed6ef566853d
Author: Olivier Fourdan <ofourdan at redhat.com>
Date:   Mon Apr 28 14:59:46 2025 +0200

    xfree86: Check for RandR provider functions
    
    Changing XRandR provider properties if the driver has set no provider
    function such as the modesetting driver will cause a NULL pointer
    dereference and a crash of the Xorg server.
    
    Related to CVE-2025-49180
    
    This issue was discovered by Nils Emmerich <nemmerich at ernw.de> and
    reported by Julian Suleder via ERNW Vulnerability Disclosure.
    
    Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>
    Reviewed-by: Peter Hutterer <peter.hutterer at who-t.net>
    Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2024>

diff --git a/hw/xfree86/modes/xf86RandR12.c b/hw/xfree86/modes/xf86RandR12.c
index ddcf5e748..bf33da377 100644
--- a/hw/xfree86/modes/xf86RandR12.c
+++ b/hw/xfree86/modes/xf86RandR12.c
@@ -2146,7 +2146,8 @@ xf86RandR14ProviderSetProperty(ScreenPtr pScreen,
     /* If we don't have any property handler, then we don't care what the
      * user is setting properties to.
      */
-    if (config->provider_funcs->set_property == NULL)
+    if (config->provider_funcs == NULL ||
+        config->provider_funcs->set_property == NULL)
         return TRUE;
 
     /*
@@ -2164,7 +2165,8 @@ xf86RandR14ProviderGetProperty(ScreenPtr pScreen,
     ScrnInfoPtr pScrn = xf86ScreenToScrn(pScreen);
     xf86CrtcConfigPtr config = XF86_CRTC_CONFIG_PTR(pScrn);
 
-    if (config->provider_funcs->get_property == NULL)
+    if (config->provider_funcs == NULL ||
+        config->provider_funcs->get_property == NULL)
         return TRUE;
 
     /* Should be safe even w/o vtSema */
commit 3c3a4b767b16174d3213055947ea7f4f88e10ec6
Author: Olivier Fourdan <ofourdan at redhat.com>
Date:   Tue May 20 15:18:19 2025 +0200

    randr: Check for overflow in RRChangeProviderProperty()
    
    A client might send a request causing an integer overflow when computing
    the total size to allocate in RRChangeProviderProperty().
    
    To avoid the issue, check that total length in bytes won't exceed the
    maximum integer value.
    
    CVE-2025-49180
    
    This issue was discovered by Nils Emmerich <nemmerich at ernw.de> and
    reported by Julian Suleder via ERNW Vulnerability Disclosure.
    
    Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>
    Reviewed-by: Peter Hutterer <peter.hutterer at who-t.net>
    Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2024>

diff --git a/randr/rrproviderproperty.c b/randr/rrproviderproperty.c
index 69f66ed27..0c3dcd1bc 100644
--- a/randr/rrproviderproperty.c
+++ b/randr/rrproviderproperty.c
@@ -182,7 +182,8 @@ RRChangeProviderProperty(RRProviderPtr provider, Atom property, Atom type,
 
     if (mode == PropModeReplace || len > 0) {
         void *new_data = NULL, *old_data = NULL;
-
+        if (total_len > MAXINT / size_in_bytes)
+            return BadValue;
         total_size = total_len * size_in_bytes;
         new_value.data = (void *) malloc(total_size);
         if (!new_value.data && total_size) {
commit 2bde9ca49a8fd9a1e6697d5e7ef837870d66f5d4
Author: Olivier Fourdan <ofourdan at redhat.com>
Date:   Mon Apr 28 11:47:15 2025 +0200

    record: Check for overflow in RecordSanityCheckRegisterClients()
    
    The RecordSanityCheckRegisterClients() checks for the request length,
    but does not check for integer overflow.
    
    A client might send a very large value for either the number of clients
    or the number of protocol ranges that will cause an integer overflow in
    the request length computation, defeating the check for request length.
    
    To avoid the issue, explicitly check the number of clients against the
    limit of clients (which is much lower than an maximum integer value) and
    the number of protocol ranges (multiplied by the record length) do not
    exceed the maximum integer value.
    
    This way, we ensure that the final computation for the request length
    will not overflow the maximum integer limit.
    
    CVE-2025-49179
    
    This issue was discovered by Nils Emmerich <nemmerich at ernw.de> and
    reported by Julian Suleder via ERNW Vulnerability Disclosure.
    
    Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>
    Reviewed-by: Peter Hutterer <peter.hutterer at who-t.net>
    Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2024>

diff --git a/record/record.c b/record/record.c
index d8e730972..fd6d0fd43 100644
--- a/record/record.c
+++ b/record/record.c
@@ -37,6 +37,7 @@ and Jim Haggerty of Metheus.
 #include "dix/cursor_priv.h"
 #include "dix/eventconvert.h"
 #include "os/client_priv.h"
+#include "os/osdep.h"
 
 #include "dixstruct.h"
 #include "extnsionst.h"
@@ -1299,6 +1300,13 @@ RecordSanityCheckRegisterClients(RecordContextPtr pContext, ClientPtr client,
     int i;
     XID recordingClient;
 
+    /* LimitClients is 2048 at max, way less that MAXINT */
+    if (stuff->nClients > LimitClients)
+        return BadValue;
+
+    if (stuff->nRanges > (MAXINT - 4 * stuff->nClients) / SIZEOF(xRecordRange))
+        return BadValue;
+
     if (((client->req_len << 2) - SIZEOF(xRecordRegisterClientsReq)) !=
         4 * stuff->nClients + SIZEOF(xRecordRange) * stuff->nRanges)
         return BadLength;
commit d55c54cecb5e83eaa2d56bed5cc4461f9ba318c2
Author: Olivier Fourdan <ofourdan at redhat.com>
Date:   Mon Apr 28 10:46:03 2025 +0200

    os: Account for bytes to ignore when sharing input buffer
    
    When reading requests from the clients, the input buffer might be shared
    and used between different clients.
    
    If a given client sends a full request with non-zero bytes to ignore,
    the bytes to ignore may still be non-zero even though the request is
    full, in which case the buffer could be shared with another client who's
    request will not be processed because of those bytes to ignore, leading
    to a possible hang of the other client request.
    
    To avoid the issue, make sure we have zero bytes to ignore left in the
    input request when sharing the input buffer with another client.
    
    CVE-2025-49178
    
    This issue was discovered by Nils Emmerich <nemmerich at ernw.de> and
    reported by Julian Suleder via ERNW Vulnerability Disclosure.
    
    Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>
    Reviewed-by: Peter Hutterer <peter.hutterer at who-t.net>
    Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2024>

diff --git a/os/io.c b/os/io.c
index 3e39c10e6..e7b76b9ce 100644
--- a/os/io.c
+++ b/os/io.c
@@ -441,7 +441,7 @@ ReadRequestFromClient(ClientPtr client)
      */
 
     gotnow -= needed;
-    if (!gotnow)
+    if (!gotnow && !oci->ignoreBytes)
         AvailableInput = oc;
     if (move_header) {
         if (client->req_len < bytes_to_int32(sizeof(xBigReq) - sizeof(xReq))) {
commit ab02fb96b1c701c3bb47617d965522c34befa6af
Author: Olivier Fourdan <ofourdan at redhat.com>
Date:   Mon Apr 28 10:05:36 2025 +0200

    xfixes: Check request length for SetClientDisconnectMode
    
    The handler of XFixesSetClientDisconnectMode does not check the client
    request length.
    
    A client could send a shorter request and read data from a former
    request.
    
    Fix the issue by checking the request size matches.
    
    CVE-2025-49177
    
    This issue was discovered by Nils Emmerich <nemmerich at ernw.de> and
    reported by Julian Suleder via ERNW Vulnerability Disclosure.
    
    Fixes: e167299f6 - xfixes: Add ClientDisconnectMode
    Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>
    Reviewed-by: Peter Hutterer <peter.hutterer at who-t.net>
    Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2024>

diff --git a/xfixes/disconnect.c b/xfixes/disconnect.c
index 937d6a4be..5b2945a4a 100644
--- a/xfixes/disconnect.c
+++ b/xfixes/disconnect.c
@@ -66,6 +66,7 @@ ProcXFixesSetClientDisconnectMode(ClientPtr client)
     ClientDisconnectPtr pDisconnect = GetClientDisconnect(client);
 
     REQUEST(xXFixesSetClientDisconnectModeReq);
+    REQUEST_SIZE_MATCH(xXFixesSetClientDisconnectModeReq);
 
     pDisconnect->disconnect_mode = stuff->disconnect_mode;
 
@@ -76,7 +77,7 @@ int _X_COLD
 SProcXFixesSetClientDisconnectMode(ClientPtr client)
 {
     REQUEST(xXFixesSetClientDisconnectModeReq);
-    REQUEST_AT_LEAST_SIZE(xXFixesSetClientDisconnectModeReq);
+    REQUEST_SIZE_MATCH(xXFixesSetClientDisconnectModeReq);
 
     swapl(&stuff->disconnect_mode);
 
commit 03731b326a80b582e48d939fe62cb1e2b10400d9
Author: Olivier Fourdan <ofourdan at redhat.com>
Date:   Mon Apr 7 16:13:34 2025 +0200

    os: Do not overflow the integer size with BigRequest
    
    The BigRequest extension allows requests larger than the 16-bit length
    limit.
    
    It uses integers for the request length and checks for the size not to
    exceed the maxBigRequestSize limit, but does so after translating the
    length to integer by multiplying the given size in bytes by 4.
    
    In doing so, it might overflow the integer size limit before actually
    checking for the overflow, defeating the purpose of the test.
    
    To avoid the issue, make sure to check that the request size does not
    overflow the maxBigRequestSize limit prior to any conversion.
    
    The caller Dispatch() function however expects the return value to be in
    bytes, so we cannot just return the converted value in case of error, as
    that would also overflow the integer size.
    
    To preserve the existing API, we use a negative value for the X11 error
    code BadLength as the function only return positive values, 0 or -1 and
    update the caller Dispatch() function to take that case into account to
    return the error code to the offending client.
    
    CVE-2025-49176
    
    This issue was discovered by Nils Emmerich <nemmerich at ernw.de> and
    reported by Julian Suleder via ERNW Vulnerability Disclosure.
    
    Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>
    Reviewed-by: Michel Dänzer <mdaenzer at redhat.com>
    Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2024>

diff --git a/dix/dispatch.c b/dix/dispatch.c
index b3e5feacc..2308cfe6d 100644
--- a/dix/dispatch.c
+++ b/dix/dispatch.c
@@ -527,9 +527,10 @@ Dispatch(void)
 
                 /* now, finally, deal with client requests */
                 result = ReadRequestFromClient(client);
-                if (result <= 0) {
-                    if (result < 0)
-                        CloseDownClient(client);
+                if (result == 0)
+                    break;
+                else if (result == -1) {
+                    CloseDownClient(client);
                     break;
                 }
 
@@ -550,7 +551,7 @@ Dispatch(void)
                                           client->index,
                                           client->requestBuffer);
 #endif
-                if (result > (maxBigRequestSize << 2))
+                if (result < 0 || result > (maxBigRequestSize << 2))
                     result = BadLength;
                 else {
                     result = XaceHookDispatch(client, client->majorOp);
diff --git a/os/io.c b/os/io.c
index 1fffaf62c..3e39c10e6 100644
--- a/os/io.c
+++ b/os/io.c
@@ -300,6 +300,10 @@ ReadRequestFromClient(ClientPtr client)
                 needed = get_big_req_len(request, client);
         }
         client->req_len = needed;
+        if (needed > MAXINT >> 2) {
+            /* Check for potential integer overflow */
+            return -(BadLength);
+        }
         needed <<= 2;           /* needed is in bytes now */
     }
     if (gotnow < needed) {
commit 0885e0b26225c90534642fe911632ec0779eebee
Author: Olivier Fourdan <ofourdan at redhat.com>
Date:   Fri Mar 28 09:43:52 2025 +0100

    render: Avoid 0 or less animated cursors
    
    Animated cursors use a series of cursors that the client can set.
    
    By default, the Xserver assumes at least one cursor is specified
    while a client may actually pass no cursor at all.
    
    That causes an out-of-bound read creating the animated cursor and a
    crash of the Xserver:
    
     | Invalid read of size 8
     |    at 0x5323F4: AnimCursorCreate (animcur.c:325)
     |    by 0x52D4C5: ProcRenderCreateAnimCursor (render.c:1817)
     |    by 0x52DC80: ProcRenderDispatch (render.c:1999)
     |    by 0x4A1E9D: Dispatch (dispatch.c:560)
     |    by 0x4B0169: dix_main (main.c:284)
     |    by 0x4287F5: main (stubmain.c:34)
     |  Address 0x59aa010 is 0 bytes after a block of size 0 alloc'd
     |    at 0x48468D3: reallocarray (vg_replace_malloc.c:1803)
     |    by 0x52D3DA: ProcRenderCreateAnimCursor (render.c:1802)
     |    by 0x52DC80: ProcRenderDispatch (render.c:1999)
     |    by 0x4A1E9D: Dispatch (dispatch.c:560)
     |    by 0x4B0169: dix_main (main.c:284)
     |    by 0x4287F5: main (stubmain.c:34)
     |
     | Invalid read of size 2
     |    at 0x5323F7: AnimCursorCreate (animcur.c:325)
     |    by 0x52D4C5: ProcRenderCreateAnimCursor (render.c:1817)
     |    by 0x52DC80: ProcRenderDispatch (render.c:1999)
     |    by 0x4A1E9D: Dispatch (dispatch.c:560)
     |    by 0x4B0169: dix_main (main.c:284)
     |    by 0x4287F5: main (stubmain.c:34)
     |  Address 0x8 is not stack'd, malloc'd or (recently) free'd
    
    To avoid the issue, check the number of cursors specified and return a
    BadValue error in both the proc handler (early) and the animated cursor
    creation (as this is a public function) if there is 0 or less cursor.
    
    CVE-2025-49175
    
    This issue was discovered by Nils Emmerich <nemmerich at ernw.de> and
    reported by Julian Suleder via ERNW Vulnerability Disclosure.
    
    Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>
    Reviewed-by: José Expósito <jexposit at redhat.com>
    Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2024>

diff --git a/render/animcur.c b/render/animcur.c
index f906cd813..1194cee7e 100644
--- a/render/animcur.c
+++ b/render/animcur.c
@@ -305,6 +305,9 @@ AnimCursorCreate(CursorPtr *cursors, CARD32 *deltas, int ncursor,
     int rc = BadAlloc, i;
     AnimCurPtr ac;
 
+    if (ncursor <= 0)
+        return BadValue;
+
     for (i = 0; i < screenInfo.numScreens; i++)
         if (!GetAnimCurScreen(screenInfo.screens[i]))
             return BadImplementation;
diff --git a/render/render.c b/render/render.c
index 113f6e0c5..fe9f03c8c 100644
--- a/render/render.c
+++ b/render/render.c
@@ -1799,6 +1799,8 @@ ProcRenderCreateAnimCursor(ClientPtr client)
     ncursor =
         (client->req_len -
          (bytes_to_int32(sizeof(xRenderCreateAnimCursorReq)))) >> 1;
+    if (ncursor <= 0)
+        return BadValue;
     cursors = xallocarray(ncursor, sizeof(CursorPtr) + sizeof(CARD32));
     if (!cursors)
         return BadAlloc;


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