kernel/linux.git/drivers/media/dvb-core/dvbdev.c, branch v6.1.168

media: dvbdev: fix the logic when DVB_DYNAMIC_MINORS is not set

2024-11-22T14:37:32+00:00

commit a4aebaf6e6efff548b01a3dc49b4b9074751c15b upstream. When CONFIG_DVB_DYNAMIC_MINORS, ret is not initialized, and a semaphore is left at the wrong state, in case of errors. Make the code simpler and avoid mistakes by having just one error check logic used weather DVB_DYNAMIC_MINORS is used or not. Reported-by: kernel test robot Reported-by: Dan Carpenter Closes: https://lore.kernel.org/r/202410201717.ULWWdJv8-lkp@intel.com/ Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/9e067488d8935b8cf00959764a1fa5de85d65725.1730926254.git.mchehab+huawei@kernel.org Cc: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

media: dvbdev: prevent the risk of out of memory access

2024-11-14T12:15:12+00:00

[ Upstream commit 972e63e895abbe8aa1ccbdbb4e6362abda7cd457 ] The dvbdev contains a static variable used to store dvb minors. The behavior of it depends if CONFIG_DVB_DYNAMIC_MINORS is set or not. When not set, dvb_register_device() won't check for boundaries, as it will rely that a previous call to dvb_register_adapter() would already be enforcing it. On a similar way, dvb_device_open() uses the assumption that the register functions already did the needed checks. This can be fragile if some device ends using different calls. This also generate warnings on static check analysers like Coverity. So, add explicit guards to prevent potential risk of OOM issues. Fixes: 5dd3f3071070 ("V4L/DVB (9361): Dynamic DVB minor allocation") Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin

media: dvbdev: Initialize sbuf

2024-07-05T07:31:49+00:00

[ Upstream commit 17d1316de0d7dc1bdc5d6e3ad4efd30a9bf1a381 ] Because the size passed to copy_from_user() cannot be known beforehand, it needs to be checked during runtime with check_object_size. That makes gcc believe that the content of sbuf can be used before init. Fix: ./include/linux/thread_info.h:215:17: warning: ‘sbuf’ may be used uninitialized [-Wmaybe-uninitialized] Signed-off-by: Ricardo Ribalda Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin

media: edia: dvbdev: fix a use-after-free

2024-03-26T22:20:46+00:00

[ Upstream commit 8c64f4cdf4e6cc5682c52523713af8c39c94e6d5 ] In dvb_register_device, *pdvbdev is set equal to dvbdev, which is freed in several error-handling paths. However, *pdvbdev is not set to NULL after dvbdev's deallocation, causing use-after-frees in many places, for example, in the following call chain: budget_register |-> dvb_dmxdev_init |-> dvb_register_device |-> dvb_dmxdev_release |-> dvb_unregister_device |-> dvb_remove_device |-> dvb_device_put |-> kref_put When calling dvb_unregister_device, dmxdev->dvbdev (i.e. *pdvbdev in dvb_register_device) could point to memory that had been freed in dvb_register_device. Thereafter, this pointer is transferred to kref_put and triggering a use-after-free. Link: https://lore.kernel.org/linux-media/20240203134046.3120099-1-alexious@zju.edu.cn Fixes: b61901024776 ("V4L/DVB (5244): Dvbdev: fix illegal re-usage of fileoperations struct") Signed-off-by: Zhipeng Lu Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin

media: dvbdev: drop refcount on error path in dvb_device_open()

2024-01-25T23:27:35+00:00

[ Upstream commit a2dd235df435a05d389240be748909ada91201d2 ] If call to file->f_op->open() fails, then call dvb_device_put(dvbdev). Fixes: 0fc044b2b5e2 ("media: dvbdev: adopts refcnt to avoid UAF") Signed-off-by: Dan Carpenter Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin

media: dvb-core: Fix use-after-free due to race at dvb_register_device()

2023-06-09T08:34:12+00:00

[ Upstream commit 627bb528b086b4136315c25d6a447a98ea9448d3 ] dvb_register_device() dynamically allocates fops with kmemdup() to set the fops->owner. And these fops are registered in 'file->f_ops' using replace_fops() in the dvb_device_open() process, and kfree()d in dvb_free_device(). However, it is not common to use dynamically allocated fops instead of 'static const' fops as an argument of replace_fops(), and UAF may occur. These UAFs can occur on any dvb type using dvb_register_device(), such as dvb_dvr, dvb_demux, dvb_frontend, dvb_net, etc. So, instead of kfree() the fops dynamically allocated in dvb_register_device() in dvb_free_device() called during the .disconnect() process, kfree() it collectively in exit_dvbdev() called when the dvbdev.c module is removed. Link: https://lore.kernel.org/linux-media/20221117045925.14297-4-imv4bel@gmail.com Signed-off-by: Hyunwoo Kim Reported-by: kernel test robot Reported-by: Dan Carpenter Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin

media: dvb-core: Fix double free in dvb_register_device()

2023-01-07T10:11:49+00:00

commit 6b0d0477fce747d4137aa65856318b55fba72198 upstream. In function dvb_register_device() -> dvb_register_media_device() -> dvb_create_media_entity(), dvb->entity is allocated and initialized. If the initialization fails, it frees the dvb->entity, and return an error code. The caller takes the error code and handles the error by calling dvb_media_device_free(), which unregisters the entity and frees the field again if it is not NULL. As dvb->entity may not NULLed in dvb_create_media_entity() when the allocation of dvbdev->pad fails, a double free may occur. This may also cause an Use After free in media_device_unregister_entity(). Fix this by storing NULL to dvb->entity when it is freed. Link: https://lore.kernel.org/linux-media/20220426052921.2088416-1-keitasuzuki.park@sslab.ics.keio.ac.jp Fixes: fcd5ce4b3936 ("media: dvb-core: fix a memory leak bug") Cc: stable@vger.kernel.org Cc: Wenwen Wang Signed-off-by: Keita Suzuki Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman

media: dvbdev: fix refcnt bug

2022-12-31T12:33:12+00:00

commit 3a664569b71b0a52be5ffb9fb87cc4f83d29bd71 upstream. Previous commit initialize the dvbdev->ref before the template copy, which will overwrite the reference and cause refcnt bug. refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 1 at lib/refcount.c:25 refcount_warn_saturate+0x17c/0x1f0 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc6-next-20221128-syzkaller #0 ... RIP: 0010:refcount_warn_saturate+0x17c/0x1f0 lib/refcount.c:25 RSP: 0000:ffffc900000678d0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88813ff58000 RSI: ffffffff81660e7c RDI: fffff5200000cf0c RBP: ffff888022a45010 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000000 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88823ffff000 CR3: 000000000c48e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:199 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] kref_get include/linux/kref.h:45 [inline] dvb_device_get drivers/media/dvb-core/dvbdev.c:585 [inline] dvb_register_device+0xe83/0x16e0 drivers/media/dvb-core/dvbdev.c:517 ... Just place the kref_init at correct position. Reported-by: syzbot+fce48a3dd3368645bd6c@syzkaller.appspotmail.com Fixes: 0fc044b2b5e2 ("media: dvbdev: adopts refcnt to avoid UAF") Signed-off-by: Lin Ma Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman

media: dvbdev: adopts refcnt to avoid UAF

2022-12-31T12:33:03+00:00

[ Upstream commit 0fc044b2b5e2d05a1fa1fb0d7f270367a7855d79 ] dvb_unregister_device() is known that prone to use-after-free. That is, the cleanup from dvb_unregister_device() releases the dvb_device even if there are pointers stored in file->private_data still refer to it. This patch adds a reference counter into struct dvb_device and delays its deallocation until no pointer refers to the object. Link: https://lore.kernel.org/linux-media/20220807145952.10368-1-linma@zju.edu.cn Signed-off-by: Lin Ma Reported-by: kernel test robot Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin

media: dvb-core: Convert to SPDX identifier

2021-11-19T15:22:13+00:00

use SPDX-License-Identifier instead of a verbose license text and remove verbose license text. Link: https://lore.kernel.org/linux-media/20210916020018.8550-1-caihuoqing@baidu.com Signed-off-by: Cai Huoqing Signed-off-by: Mauro Carvalho Chehab