✗ CI.checkpatch: warning for drm/xe: Don't keep stale pointer to bo->ggtt_node

[Patchwork]

== Series Details ==

Series: drm/xe: Don't keep stale pointer to bo->ggtt_node
URL   : https://patchwork.freedesktop.org/series/138351/
State : warning

== Summary ==

+ KERNEL=/kernel
+ git clone https://gitlab.freedesktop.org/drm/maintainer-tools mt
Cloning into 'mt'...
warning: redirecting to https://gitlab.freedesktop.org/drm/maintainer-tools.git/
+ git -C mt rev-list -n1 origin/master
c62d7e164862503a3662a095da1c6c9014248cb2
+ cd /kernel
+ git config --global --add safe.directory /kernel
+ git log -n1
commit 1087e4ded0074100ac72b13e76a3a398090434c5
Author: Michal Wajdeczko <michal.wajdeczko at intel.com>
Date:   Sat Sep 7 00:03:48 2024 +0200

    drm/xe: Don't keep stale pointer to bo->ggtt_node
    
    When we fail to map a BO in the GGTT, we release our GGTT node
    placeholder, but leave stale bo->ggtt_node pointer to it, which
    triggers an assert immediately followed by a crash, due to UAF:
    
    [ ] xe 0000:00:02.0: [drm] Assertion `bo->ggtt_node->base.size == bo->size` failed!
    [ ] WARNING: CPU: 4 PID: 126 at drivers/gpu/drm/xe/xe_ggtt.c:689 xe_ggtt_remove_bo+0x1d9/0x250 [xe]
    [ ] RIP: 0010:xe_ggtt_remove_bo+0x1d9/0x250 [xe]
    [ ] Call Trace:
    [ ]  <TASK>
    [ ]  ? __warn+0x88/0x190
    [ ]  ? xe_ggtt_remove_bo+0x1d9/0x250 [xe]
    [ ]  ? report_bug+0x1c3/0x1d0
    [ ]  ? handle_bug+0x42/0x70
    [ ]  ? exc_invalid_op+0x14/0x70
    [ ]  ? asm_exc_invalid_op+0x16/0x20
    [ ]  ? xe_ggtt_remove_bo+0x1d9/0x250 [xe]
    [ ]  ? xe_ggtt_remove_bo+0x1d9/0x250 [xe]
    [ ]  xe_ttm_bo_destroy+0x11f/0x260 [xe]
    [ ]  ? ttm_bo_release+0x31c/0x350 [ttm]
    [ ]  ? __mutex_unlock_slowpath+0x35/0x270
    [ ]  __xe_bo_create_locked+0x4a0/0x550 [xe]
    [ ]  ? mark_held_locks+0x49/0x80
    [ ]  xe_bo_create_pin_map_at+0x37/0x200 [xe]
    [ ]  xe_bo_create_pin_map+0x11/0x20 [xe]
    
    While around, for similar reason, also don't keep an error pointer
    if we fail to allocate ggtt_node placeholder.
    
    Fixes: 34e804220f69 ("drm/xe: Make xe_ggtt_node struct independent")
    Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
    Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
    Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
+ /mt/dim checkpatch 217031ad4c962ee8b1b7ac4b30323b4e2ac6d12a drm-intel
1087e4ded007 drm/xe: Don't keep stale pointer to bo->ggtt_node
-:10: WARNING:COMMIT_LOG_LONG_LINE: Prefer a maximum 75 chars per line (possible unwrapped commit description?)
#10: 
[ ] xe 0000:00:02.0: [drm] Assertion `bo->ggtt_node->base.size == bo->size` failed!

total: 0 errors, 1 warnings, 0 checks, 21 lines checked