mirror of
https://gitlab.freedesktop.org/xorg/xserver.git
synced 2025-12-24 10:10:05 +01:00
4308f5d3d1
If a client is in the process of being closed down, then its client->osPrivate pointer will be set to NULL by CloseDownConnection. This can cause a crash if freeing the client's resources results in a call to AttendClient. For example, if the client has a pending sync fence: Thread 1 "X" received signal SIGSEGV, Segmentation fault. AttendClient (client=0x5571c4aed9a0) at ../os/connection.c:942 (gdb) bt #0 AttendClient (client=0x5571c4aed9a0) at ../os/connection.c:942 #1 0x00005571c3dbb865 in SyncAwaitTriggerFired (pTrigger=<optimized out>) at ../Xext/sync.c:694 #2 0x00005571c3dd5749 in miSyncDestroyFence (pFence=0x5571c5063980) at ../miext/sync/misync.c:120 #3 0x00005571c3dbbc69 in FreeFence (obj=<optimized out>, id=<optimized out>) at ../Xext/sync.c:1909 #4 0x00005571c3d7a01d in doFreeResource (res=0x5571c506e3d0, skip=skip@entry=0) at ../dix/resource.c:880 #5 0x00005571c3d7b1dc in FreeClientResources (client=0x5571c4aed9a0) at ../dix/resource.c:1146 #6 FreeClientResources (client=0x5571c4aed9a0) at ../dix/resource.c:1109 #7 0x00005571c3d5525f in CloseDownClient (client=0x5571c4aed9a0) at ../dix/dispatch.c:3473 #8 0x00005571c3d55eeb in Dispatch () at ../dix/dispatch.c:492 #9 0x00005571c3d59e96 in dix_main (argc=3, argv=0x7ffe7854bc28, envp=<optimized out>) at ../dix/main.c:276 #10 0x00007fea4837cb6b in __libc_start_main (main=0x5571c3d1d060 <main>, argc=3, argv=0x7ffe7854bc28, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffe7854bc18) at ../csu/libc-start.c:308 #11 0x00005571c3d1d09a in _start () at ../Xext/sync.c:2378 (gdb) print client->osPrivate $1 = (void *) 0x0 Since the client is about to be freed, its ignore count doesn't matter and AttendClient can simply be a no-op. Check for client->clientGone in AttendClient and remove similar checks from two callers that had them. Signed-off-by: Aaron Plattner <aplattner@nvidia.com> |
||
|---|---|---|
| .. | ||
| .gitignore | ||
| access.c | ||
| auth.c | ||
| backtrace.c | ||
| busfault.c | ||
| client.c | ||
| connection.c | ||
| inputthread.c | ||
| io.c | ||
| log.c | ||
| Makefile.am | ||
| meson.build | ||
| mitauth.c | ||
| oscolor.c | ||
| osdep.h | ||
| osinit.c | ||
| ospoll.c | ||
| ospoll.h | ||
| reallocarray.c | ||
| rpcauth.c | ||
| strcasecmp.c | ||
| strcasestr.c | ||
| strlcat.c | ||
| strlcpy.c | ||
| strndup.c | ||
| timingsafe_memcmp.c | ||
| utils.c | ||
| WaitFor.c | ||
| xdmauth.c | ||
| xdmcp.c | ||
| xprintf.c | ||
| xserver_poll.c | ||
| xsha1.c | ||
| xstrans.c | ||