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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?cmNEU3VockVOUTluZGg0SStyRXJma3N2ZUtXT2oxYTlKMjBwaURpNWdlaGt1?= =?utf-8?B?dGNqK2E1aEROOUlraEpOVkloVGRUdWdSZ1FhL2daRmhZNWFDeGhkeG5RdVNh?= =?utf-8?B?STNmZkJEMUhQVVJDU3JxQUh2YjRTTEo3dkxvZ211ME1uQkNMU3J6dnBnaEhM?= =?utf-8?B?STRjMWgxYjV6RkczdXI4Si9JVDhhQUF4THZZUUNVZmRnN1V5VHZ1RTdPRzhr?= =?utf-8?B?ZUM2QUg5SXEvWjArRFZ5alp3Ylc4U2l0b1haTUVBM2Z6QXRIb1NZYlNzbmha?= =?utf-8?B?OVJLMjdlazZKQmU4M2VRL2tETWZiVWpSY1FBRXBLNWR5d2NYd2p4anE0RUFn?= =?utf-8?B?aDRZelBISU1xaXRGQW5pYjA2RVFVdC9EeTV0Yzk3ZnYvelBMVU1pd2pyaHdG?= =?utf-8?B?aTRDdmdwQ2hDdmZOR1dZeWlHUkJUbExTZndxVWRPNGZSK0MzZU1icWNPTmh1?= =?utf-8?B?UjVHUFR2SDZsb1JSNFpFc1VpYnZnOVZVek5jQzJaWDd0MnZqcElIaDRKL0ly?= =?utf-8?B?YmRyUUZoUWY5VEtvNVhwVkIzVlVBbjFJTDIxS3FMYzFiSS9YaUpxZTA2VW5D?= =?utf-8?B?ZjVEMFltanNYMGNGZFA5VGlVSjNqVTFXL0Z1WFc0cTluNGVmUk9ZNzZlaklm?= =?utf-8?B?TnlhREw4SjBXMXh0eEl0TG90MUZFaEdZZTNadVBuUmdNaytZWDhzL2VsQWpW?= =?utf-8?B?K2YxK3Z0aXd0WHIwblRQeU9nTXEvZ3daenhIaGtZcHZESjZMeDJOK2ZEZDJr?= =?utf-8?B?VWZEd04rU09VS252cll2czR3WldmbW1CUCtjMFZlUWhtakpVcEdVQmswclVv?= =?utf-8?B?aUFCck4zcTdpaTNDeTYrY1hBTnJlcmk4dEVhL0l6aFNTUDkxQndMcy94WVlo?= =?utf-8?B?bGlSL3VOc2U3dWdNbm0vczY5M2FLRFpyLzdiMnZXM3haY2ZUcmhvejR4Vklo?= =?utf-8?B?WTltYWxtTXl5QnFvKzZtcnh2M24ybkxpNjcxODFCNXpVMWJtakg5QWhCQVds?= =?utf-8?B?eE56bGUzbHFSVzdmVitHUWF3ZElnUWs5NEp4MjRIWXdVUWU0UGthVGlkYkFT?= =?utf-8?B?ejE2ZlVtaHpqQm5rUHNpU0NLUWVzYUFlYy93L0tjcG5WbEhTMzRYMmFuYmlJ?= =?utf-8?B?OEVJTVZIQWhZWkpabGF1UVY1MUN6NnFLQ2V0UXRaRG93VlJNTHdBbDhxWVdC?= =?utf-8?B?d0Q2VjVzYndlTnI5VDVrRjN3WjJZOFViZDFGWDJhSHROOE9ZM2dSOGhiaEdF?= =?utf-8?B?UHhPS1ZISWF3Nmx3TnJIUk91dU5VTmdiQzMxTW5YdEVDdGZ2b1hlVDd2bUc4?= =?utf-8?B?cXhXQlNrTU5EOFV4RENBYThZTDVVdmVEQ2N5QTBXQ0lKU1hnM1RJSUdkRlBy?= =?utf-8?B?NHpFbnVVdEZ5Rm03ek5wZTBCVmtzVk1UUUcwcE5aZUg3MWtpRXRjSHNpeVZk?= =?utf-8?B?OE9TWWhXQTVkZzhHeGJOOTgvRDB3Vkl2TzdDQXFCbnJQWHQzNDI3NGRDS0Js?= =?utf-8?B?VFVlZVJUWXpYTzdxeHhmbmhkdFBaQTRrZlRJcGxaMXZBaVQ3eHRyZ1dxUExw?= =?utf-8?B?czNDTkFBdVRhRzhRMUt2Y1o4cjdFYnVHcStZYnVhb2RtNU12Tm9qNVN0ZHFm?= =?utf-8?B?dVIwL3VRbjdEcldwdXU2aFZETUY3SGN6WUhRT0FaZVkrb05iZlhyM29Dcisr?= =?utf-8?B?bElRL1lhVFFQVTVJVEpHa21pZkhRUitUbkRJVGNKTlQ5ZEVUMVB0TDg3SHQy?= =?utf-8?B?bnllV2N6Z0VNTHdIU2w0bXBGWkk0eUVoUVc3Y3BrN1NNWHUvbnNsWkFKY01K?= =?utf-8?B?Tlg4ZEJMekprc0NwVno1YWNKbHpTeUZ4SkNudkMzQTdPVjR3SEtIUFp6ODNy?= =?utf-8?B?T21jcXpUNVJzNGNLanFwS2tSRlo4UHN4RXBrMTV5d1NKWDF1eDBqbVVwNWVn?= =?utf-8?B?a1hINS9KOWwzcVprMCt2NVRXMEpMMDMyR3RIZ0VLd0RGb0IzejEyYnhWZ25r?= =?utf-8?B?N3dZWG1UVWE2VjA4UW9qc1hzdG95alNkQjdjYlB3SkV5RVpHekZqV1ZYazhz?= =?utf-8?B?bm5uM1ZFL0NNSUNTTllmZVlFdVp1Z3FJOG0xNmtIYmhZR3lxNkVJQ2dBdEg3?= =?utf-8?Q?AaEt9yxsU6XSKOPXxIBxkllbu?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 3f505b8c-83c1-48f7-7763-08dab7e2f1f2 X-MS-Exchange-CrossTenant-AuthSource: BN8PR12MB3587.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Oct 2022 06:17:37.8225 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 2mMYtOOZlR6xYF24sbr67mf6YR5ydmSyVSFD4udni0eNPXsyZ08Ac4pCbDeO0eH7 X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN9PR12MB5305 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 27.10.22 um 00:46 schrieb Dmitry Osipenko: > The drm_gem_vunmap() will crash with a NULL dereference if the passed > object pointer is NULL. It wasn't a problem before we added the locking > support to drm_gem_vunmap function because the mapping argument was always > NULL together with the object. Make drm_gem_vunmap() functions to handle > the NULL pointers better. > > Reported-by: Dan Carpenter > Link: https://lore.kernel.org/dri-devel/Y1kFEGxT8MVlf32V@kili/ > Fixes: 79e2cf2e7a19 ("drm/gem: Take reservation lock for vmap/vunmap operations") > Signed-off-by: Dmitry Osipenko > --- > drivers/gpu/drm/drm_gem.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c > index b8db675e7fb5..ee0a246ff4ac 100644 > --- a/drivers/gpu/drm/drm_gem.c > +++ b/drivers/gpu/drm/drm_gem.c > @@ -1175,11 +1175,11 @@ EXPORT_SYMBOL(drm_gem_vmap); > > void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map) > { > - dma_resv_assert_held(obj->resv); > - > - if (iosys_map_is_null(map)) > + if (!obj || iosys_map_is_null(map)) > return; I'm not very keen about that. Calling a function with all parameters NULL doesn't make much sense and is clearly a coding error. Hiding that somehow doesn't help but rather makes things worse. The only execption to that are things like kfree() or *_put() which work with the lifetime of objects. Why is the static checker complaining about that in the first place? Regards, Christian. > > + dma_resv_assert_held(obj->resv); > + > if (obj->funcs->vunmap) > obj->funcs->vunmap(obj, map); > > @@ -1202,6 +1202,9 @@ EXPORT_SYMBOL(drm_gem_vmap_unlocked); > > void drm_gem_vunmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map) > { > + if (!obj || iosys_map_is_null(map)) > + return; > + > dma_resv_lock(obj->resv, NULL); > drm_gem_vunmap(obj, map); > dma_resv_unlock(obj->resv);