CVE-2024-26875media: pvrusb2: fix uaf in pvr2_context_set_notify

Official description

In the Linux kernel, the following vulnerability has been resolved: media: pvrusb2: fix uaf in pvr2_context_set_notify [Syzbot reported] BUG: KASAN: slab-use-after-free in pvr2_context_set_notify+0x2c4/0x310 drivers/media/usb/pvrusb2/pvrusb2-context.c:35 Read of size 4 at addr ffff888113aeb0d8 by task kworker/1:1/26 CPU: 1 PID: 26 Comm: kworker/1:1 Not tainted 6.8.0-rc1-syzkaller-00046-gf1a27f081c1f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: usb_hub_wq hub_event Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc4/0x620 mm/kasan/report.c:488 kasan_report+0xda/0x110 mm/kasan/report.c:601 pvr2_context_set_notify+0x2c4/0x310 drivers/media/usb/pvrusb2/pvrusb2-context.c:35 pvr2_context_notify drivers/media/usb/pvrusb2/pvrusb2-context.c:95 [inline] pvr2_context_disconnect+0x94/0xb0 drivers/media/usb/pvrusb2/pvrusb2-context.c:272 Freed by task 906: kasan_save_stack+0x33/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640 poison_slab_object mm/kasan/common.c:241 [inline] __kasan_slab_free+0x106/0x1b0 mm/kasan/common.c:257 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kfree+0x105/0x340 mm/slub.c:4409 pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:137 [inline] pvr2_context_thread_func+0x69d/0x960 drivers/media/usb/pvrusb2/pvrusb2-context.c:158 [Analyze] Task A set disconnect_flag = !0, which resulted in Task B's condition being met and releasing mp, leading to this issue. [Fix] Place the disconnect_flag assignment operation after all code in pvr2_context_disconnect() to avoid this issue.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/ed8000e1e8e9684ab6c30cf2b526c0cea039929c
• https://git.kernel.org/stable/c/d29ed08964cec8b9729bc55c7bb23f679d7a18fb
• https://git.kernel.org/stable/c/ab896d93fd6a2cd1afeb034c3cc9226cb499209f
• https://git.kernel.org/stable/c/eb6e9dce979c08210ff7249e5e0eceb8991bfcd7
• https://git.kernel.org/stable/c/3a1ec89708d2e57e2712f46241282961b1a7a475
• https://git.kernel.org/stable/c/8e60b99f6b7ccb3badeb512f5eb613ad45904592
• https://git.kernel.org/stable/c/40cd818fae875c424a8335009db33c7b5a07de3a
• https://git.kernel.org/stable/c/eaa410e05bdf562c90b23cdf2d9327f9c4625e16
• https://git.kernel.org/stable/c/0a0b79ea55de8514e1750884e5fec77f9fdd01ee
• https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html x_transferred
• https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html x_transferred
• https://cert-portal.siemens.com/productcert/html/ssa-265688.html