In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
drm\/nouveau: fix double-free in nvif_vmm_dtor<\/p>\n
On failure, nouveau_cli_init() calls nouveau_cli_fini() to tear
\nthe client down. Then, nouveau_drm_open() also enters into its
\ncleanup path and calls nouveau_cli_fini() AGAIN. nouveau_cli_fini()
\ncalls nouveau_vmm_fini():<\/p>\n
\tvoid
\n\tnouveau_vmm_fini(struct nouveau_vmm *vmm)
\n\t{
\n\t\tnouveau_svmm_fini(&vmm->svmm);
\n\t\tnvif_vmm_dtor(&vmm->vmm);
\n\t\tvmm->cli = NULL;
\n\t}<\/p>\n
Inside nvif_vmm_dtor(), vmm->page is freed unconditionally:<\/p>\n
\tvoid
\n\tnvif_vmm_dtor(struct nvif_vmm *vmm)
\n\t{
\n\t\tkfree(vmm->page);
\n\t\tnvif_object_dtor(&vmm->object);
\n\t}<\/p>\n
vmm->page is never cleared after being freed, so the second call of
\nnvif_vmm_dtor() will cause a double-free.<\/p>\n
Found by fuzzing the nouveau driver with a modified Syzkaller:<\/p>\n
\tBUG: KASAN: double-free in nvif_vmm_dtor+0x31\/0x50 drivers\/gpu\/drm\/nouveau\/nvif\/vmm.c:194
\n\tFree of addr ffff888010fcdc30 by task syz.0.173\/2567<\/p>\n
\tCPU: 1 UID: 0 PID: 2567 Comm: syz.0.173 Not tainted 7.2.0 #24 PREEMPT(lazy)
\n\tHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04\/01\/2014
\n\tCall Trace:<\/p>\n
\t__dump_stack lib\/dump_stack.c:94 [inline]
\n\tdump_stack_lvl+0x95\/0xe0 lib\/dump_stack.c:120
\n\tprint_address_description mm\/kasan\/report.c:378 [inline]
\n\tprint_report+0xcb\/0x5a0 mm\/kasan\/report.c:482
\n\tkasan_report_invalid_free+0xaa\/0xd0 mm\/kasan\/report.c:557
\n\tcheck_slab_allocation+0xe4\/0x110 mm\/kasan\/common.c:235
\n\tkasan_slab_pre_free include\/linux\/kasan.h:199 [inline]
\n\tslab_free_hook mm\/slub.c:2622 [inline]
\n\tslab_free mm\/slub.c:6377 [inline]
\n\tkfree+0x192\/0x590 mm\/slub.c:6692
\n\tnvif_vmm_dtor+0x31\/0x50 drivers\/gpu\/drm\/nouveau\/nvif\/vmm.c:194
\n\tnouveau_vmm_fini+0x16\/0x50 drivers\/gpu\/drm\/nouveau\/nouveau_vmm.c:127
\n\tnouveau_cli_fini+0x10e\/0x210 drivers\/gpu\/drm\/nouveau\/nouveau_drm.c:225
\n\tnouveau_drm_open+0x24e\/0x740 drivers\/gpu\/drm\/nouveau\/nouveau_drm.c:1255
\n\tdrm_file_alloc+0x5f2\/0xad0 drivers\/gpu\/drm\/drm_file.c:176
\n\tdrm_open_helper+0x1d7\/0x4a0 drivers\/gpu\/drm\/drm_file.c:335
\n\tdrm_open+0x190\/0x3d0 drivers\/gpu\/drm\/drm_file.c:388
\n\tdrm_stub_open+0x1f2\/0x460 drivers\/gpu\/drm\/drm_drv.c:1211
\n\tchrdev_open+0x21c\/0x660 fs\/char_dev.c:411
\n\tdo_dentry_open+0x59d\/0x12b0 fs\/open.c:947
\n\tvfs_open+0x82\/0x390 fs\/open.c:1052
\n\tdo_open fs\/namei.c:4700 [inline]
\n\tpath_openat+0x2345\/0x3420 fs\/namei.c:4863
\n\tdo_file_open+0x207\/0x460 fs\/namei.c:4892
\n\tdo_sys_openat2+0xd1\/0x1d0 fs\/open.c:1368
\n\tdo_sys_open fs\/open.c:1374 [inline]
\n\t__do_sys_openat fs\/open.c:1390 [inline]
\n\t__se_sys_openat fs\/open.c:1385 [inline]
\n\t__x64_sys_openat+0x144\/0x200 fs\/open.c:1385
\n\tdo_syscall_x64 arch\/x86\/entry\/syscall_64.c:63 [inline]
\n\tdo_syscall_64+0x115\/0x690 arch\/x86\/entry\/syscall_64.c:94
\n\tentry_SYSCALL_64_after_hwframe+0x77\/0x7f
\n\tRIP: 0033:0x7fc6d687594d
\n\tCode: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
\n\tRSP: 002b:00007fc6d5295008 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
\n\tRAX: ffffffffffffffda RBX: 00007fc6d6b06180 RCX: 00007fc6d687594d
\n\tRDX: 0000000000022501 RSI: 0000200000000000 RDI: ffffffffffffff9c
\n\tRBP: 00007fc6d691c303 R08: 0000000000000000 R09: 0000000000000000
\n\tR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
\n\tR13: 00007fc6d6b06218 R14: 00007fc6d6b06180 R15: 00007ffd9451d760<\/p>\n
\tAllocated by task 2567 on cpu 1 at 163.593900s:
\n\tkasan_save_stack+0x24\/0x50 mm\/kasan\/common.c:57
\n\tkasan_save_track+0x17\/0x60 mm\/kasan\/common.c:78
\n\tpoison_kmalloc_redzone mm\/kasan\/common.c:398 [inline]
\n\t__kasan_kmalloc+0xaa\/0xb0 mm\/kasan\/common.c:415
\n\tkasan_kmalloc include\/linux\/kasan.h:263 [inline]
\n\t__do_kmalloc_node mm\/slub.c:5334 [inline]
\n\t__kmalloc_noprof+0x304\/0x7c0 mm\/slub.c:5359
\n\t_kmalloc_noprof include\/linux\/slab.h:992 [inline]
\n\tnvif_vmm_ctor+0x3c0\/0x7e0 drivers\/gpu\/drm\/nouveau\/nvif\/vmm.c:237
\n\tnouveau_vmm_init+0x40\/0x90 drivers\/gpu\/drm\/nouveau\/nouveau_vmm.c:134
\n\tnouveau_cli_init+0x7b9\/0
\n—truncated—<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
drm\/nouveau: fix double-free in nvif_vmm_dtor<\/p>\n
On failure, nouveau_cli_init() calls nouveau_cli_fini() to tear
\nthe client down. The<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-40987","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/40987","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=40987"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=40987"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=40987"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}