kernel/drivers/media/dvb-core/dmxdev.c, branch linux-6.9.y

media: dvb-core: Fix UAF due to refcount races at releasing

2022-11-04T15:56:43Z

The dvb-core tries to sync the releases of opened files at dvb_dmxdev_release() with two refcounts: dvbdev->users and dvr_dvbdev->users. A problem is present in those two syncs: when yet another dvb_demux_open() is called during those sync waits, dvb_demux_open() continues to process even if the device is being closed. This includes the increment of the former refcount, resulting in the leftover refcount after the sync of the latter refcount at dvb_dmxdev_release(). It ends up with use-after-free, since the function believes that all usages were gone and releases the resources. This patch addresses the problem by adding the check of dmxdev->exit flag at dvb_demux_open(), just like dvb_dvr_open() already does. With the exit flag check, the second call of dvb_demux_open() fails, hence the further corruption can be avoided. Also for avoiding the races of the dmxdev->exit flag reference, this patch serializes the dmxdev->exit set up and the sync waits with the dmxdev->mutex lock at dvb_dmxdev_release(). Without the mutex lock, dvb_demux_open() (or dvb_dvr_open()) may run concurrently with dvb_dmxdev_release(), which allows to skip the exit flag check and continue the open process that is being closed. CVE-2022-41218 is assigned to those bugs above. Reported-by: Hyunwoo Kim Cc: Link: https://lore.kernel.org/20220908132754.30532-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Hans Verkuil

media: dvb-core: Convert to SPDX identifier

2021-11-19T15:22:13Z

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

media: dmxdev: fix UAF when dvb_register_device() fails

2021-11-19T15:17:57Z

I got a use-after-free report: dvbdev: dvb_register_device: failed to create device dvb1.dvr0 (-12) ... ================================================================== BUG: KASAN: use-after-free in dvb_dmxdev_release+0xce/0x2f0 ... Call Trace: dump_stack_lvl+0x6c/0x8b print_address_description.constprop.0+0x48/0x70 kasan_report.cold+0x82/0xdb __asan_load4+0x6b/0x90 dvb_dmxdev_release+0xce/0x2f0 ... Allocated by task 7666: kasan_save_stack+0x23/0x50 __kasan_kmalloc+0x83/0xa0 kmem_cache_alloc_trace+0x22e/0x470 dvb_register_device+0x12f/0x980 dvb_dmxdev_init+0x1f3/0x230 ... Freed by task 7666: kasan_save_stack+0x23/0x50 kasan_set_track+0x20/0x30 kasan_set_free_info+0x24/0x40 __kasan_slab_free+0xf2/0x130 kfree+0xd1/0x5c0 dvb_register_device.cold+0x1ac/0x1fa dvb_dmxdev_init+0x1f3/0x230 ... When dvb_register_device() in dvb_dmxdev_init() fails, dvb_dmxdev_init() does not return a failure, and the memory pointed to by dvbdev or dvr_dvbdev is invalid at this point. If they are used subsequently, it will result in UFA or null-ptr-deref. If dvb_register_device() in dvb_dmxdev_init() fails, fix the bug by making dvb_dmxdev_init() return an error as well. Link: https://lore.kernel.org/linux-media/20211015085741.1203283-1-wanghai38@huawei.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Hulk Robot Signed-off-by: Wang Hai Signed-off-by: Mauro Carvalho Chehab

media: dmxdev: change the check for problems allocing secfeed

2021-06-09T12:45:20Z

While the logic there is right, it tricks static check analyzers, like smatch: drivers/media/dvb-core/dmxdev.c:729 dvb_dmxdev_filter_start() error: we previously assumed '*secfeed' could be null (see line 719) Because the implementation of the filter itself is made via a callback, with its real implementation at the dvbdmx_allocate_section_feed() inside dvb_demux.c. So, change the check logic to make it clear that the function will not try to use *secfeed == NULL. Signed-off-by: Mauro Carvalho Chehab

media: dvb-core: fix epoll() by calling poll_wait first

2019-02-18T19:48:37Z

The epoll function expects that whenever the poll file op is called, the poll_wait function is also called. That didn't always happen in dvb_demux_poll(), dvb_dvr_poll() and dvb_ca_en50221_io_poll(). Fix this, otherwise epoll() can timeout when it shouldn't. Signed-off-by: Hans Verkuil Reviewed-by: Sean Young Signed-off-by: Mauro Carvalho Chehab

media: dvb: dmxdev: move compat_ioctl handling to dmxdev.c

2018-09-12T15:00:51Z

All dmx ioctls are compatible, and they are only implemented in one file, so we can replace the list of commands in fs/compat_ioctl.c with a single line in dmxdev. Signed-off-by: Arnd Bergmann Signed-off-by: Mauro Carvalho Chehab

treewide: Use array_size() in vmalloc()

2018-06-12T23:19:22Z

The vmalloc() function has no 2-factor argument form, so multiplication factors need to be wrapped in array_size(). This patch replaces cases of: vmalloc(a * b) with: vmalloc(array_size(a, b)) as well as handling cases of: vmalloc(a * b * c) with: vmalloc(array3_size(a, b, c)) This does, however, attempt to ignore constant size factors like: vmalloc(4 * 1024) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( vmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | vmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( vmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(u8) * COUNT + COUNT , ...) | vmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | vmalloc( - sizeof(char) * COUNT + COUNT , ...) | vmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( vmalloc( - sizeof(TYPE) * (COUNT_ID) + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT_ID + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT_CONST + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vmalloc( - sizeof(THING) * (COUNT_ID) + array_size(COUNT_ID, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT_ID + array_size(COUNT_ID, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT_CONST + array_size(COUNT_CONST, sizeof(THING)) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ vmalloc( - SIZE * COUNT + array_size(COUNT, SIZE) , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( vmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( vmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( vmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( vmalloc(C1 * C2 * C3, ...) | vmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants. @@ expression E1, E2; constant C1, C2; @@ ( vmalloc(C1 * C2, ...) | vmalloc( - E1 * E2 + array_size(E1, E2) , ...) ) Signed-off-by: Kees Cook

media: Revert cleanup ktime_set() usage

2018-05-09T20:31:06Z

This reverts 8b0e195314fa, because media-tree drivers should use the API functions to initialize variables of type ktime_t. Cc: Thomas Gleixner Signed-off-by: Jasmin Jessich Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab

media: dvb: update buffer mmaped flags and frame counter

2018-02-23T16:44:08Z

Now that we have support for a buffer counter and for error flags, update them at DMX_DQBUF. Signed-off-by: Mauro Carvalho Chehab

media: dmxdev: Fix the logic that enables DMA mmap support

2018-02-23T10:27:10Z

Some conditions required for DVB mmap support to work are reversed. Also, the logic is not too clear. So, improve the logic, making it easier to be handled. PS.: I'm pretty sure that I fixed it while testing, but, somehow, the change got lost. Signed-off-by: Mauro Carvalho Chehab