CVE-2024-57834

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> media: vidtv: Fix a null-ptr-deref in vidtv_mux_stop_thread<br /> <br /> syzbot report a null-ptr-deref in vidtv_mux_stop_thread. [1]<br /> <br /> If dvb-&gt;mux is not initialized successfully by vidtv_mux_init() in the<br /> vidtv_start_streaming(), it will trigger null pointer dereference about mux<br /> in vidtv_mux_stop_thread().<br /> <br /> Adjust the timing of streaming initialization and check it before<br /> stopping it.<br /> <br /> [1]<br /> KASAN: null-ptr-deref in range [0x0000000000000128-0x000000000000012f]<br /> CPU: 0 UID: 0 PID: 5842 Comm: syz-executor248 Not tainted 6.13.0-rc4-syzkaller-00012-g9b2ffa6148b1 #0<br /> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024<br /> RIP: 0010:vidtv_mux_stop_thread+0x26/0x80 drivers/media/test-drivers/vidtv/vidtv_mux.c:471<br /> Code: 90 90 90 90 66 0f 1f 00 55 53 48 89 fb e8 82 2e c8 f9 48 8d bb 28 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 b6 04 02 84 c0 74 02 7e 3b 0f b6 ab 28 01 00 00 31 ff 89 ee e8<br /> RSP: 0018:ffffc90003f2faa8 EFLAGS: 00010202<br /> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff87cfb125<br /> RDX: 0000000000000025 RSI: ffffffff87d120ce RDI: 0000000000000128<br /> RBP: ffff888029b8d220 R08: 0000000000000005 R09: 0000000000000000<br /> R10: 0000000000000000 R11: 0000000000000003 R12: ffff888029b8d188<br /> R13: ffffffff8f590aa0 R14: ffffc9000581c5c8 R15: ffff888029a17710<br /> FS: 00007f7eef5156c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 00007f7eef5e635c CR3: 0000000076ca6000 CR4: 00000000003526f0<br /> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000<br /> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400<br /> Call Trace:<br /> <br /> vidtv_stop_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:209 [inline]<br /> vidtv_stop_feed+0x151/0x250 drivers/media/test-drivers/vidtv/vidtv_bridge.c:252<br /> dmx_section_feed_stop_filtering+0x90/0x160 drivers/media/dvb-core/dvb_demux.c:1000<br /> dvb_dmxdev_feed_stop.isra.0+0x1ee/0x270 drivers/media/dvb-core/dmxdev.c:486<br /> dvb_dmxdev_filter_stop+0x22a/0x3a0 drivers/media/dvb-core/dmxdev.c:559<br /> dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline]<br /> dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246<br /> __fput+0x3f8/0xb60 fs/file_table.c:450<br /> task_work_run+0x14e/0x250 kernel/task_work.c:239<br /> get_signal+0x1d3/0x2610 kernel/signal.c:2790<br /> arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337<br /> exit_to_user_mode_loop kernel/entry/common.c:111 [inline]<br /> exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]<br /> __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]<br /> syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218<br /> do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89<br /> entry_SYSCALL_64_after_hwframe+0x77/0x7f