================================================================== BUG: KASAN: slab-use-after-free in __up_read+0x633/0x760 kernel/locking/rwsem.c:1342 Read of size 8 at addr ffff888079d98868 by task syz-executor.3/7917 CPU: 1 PID: 7917 Comm: syz-executor.3 Not tainted 6.7.0-rc1-syzkaller-00213-g791c8ab095f7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Call Trace: __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:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 __up_read+0x633/0x760 kernel/locking/rwsem.c:1342 iommufd_put_object drivers/iommu/iommufd/iommufd_private.h:160 [inline] iommufd_vfio_ioas+0x46c/0x580 drivers/iommu/iommufd/vfio_compat.c:146 iommufd_fops_ioctl+0x35a/0x4e0 drivers/iommu/iommufd/main.c:404 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7fcf5687cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcf575020c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcf5699bf80 RCX: 00007fcf5687cae9 RDX: 0000000020000080 RSI: 0000000000003b88 RDI: 0000000000000003 RBP: 00007fcf568c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fcf5699bf80 R15: 00007ffea194b428 Allocated by task 7917: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc+0x59/0x90 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:721 [inline] _iommufd_object_alloc+0x26/0x1b0 drivers/iommu/iommufd/main.c:40 iommufd_ioas_alloc drivers/iommu/iommufd/ioas.c:27 [inline] iommufd_ioas_alloc_ioctl+0xaf/0x370 drivers/iommu/iommufd/ioas.c:46 iommufd_fops_ioctl+0x35a/0x4e0 drivers/iommu/iommufd/main.c:404 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b Freed by task 7920: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xc0/0x180 mm/slub.c:3822 iommufd_destroy+0x11e/0x180 drivers/iommu/iommufd/main.c:216 iommufd_fops_ioctl+0x35a/0x4e0 drivers/iommu/iommufd/main.c:404 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b The buggy address belongs to the object at ffff888079d98800 which belongs to the cache kmalloc-cg-1k of size 1024 The buggy address is located 104 bytes inside of freed 1024-byte region [ffff888079d98800, ffff888079d98c00) The buggy address belongs to the physical page: page:ffffea0001e76600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79d98 head:ffffea0001e76600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88807aadc901 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff88801304f280 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000100010 00000001ffffffff ffff88807aadc901 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5942, tgid 5936 (syz-executor.4), ts 125822262678, free_ts 125800416439 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1537 prep_new_page mm/page_alloc.c:1544 [inline] get_page_from_freelist+0xa25/0x36d0 mm/page_alloc.c:3312 __alloc_pages+0x22e/0x2420 mm/page_alloc.c:4568 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133 alloc_slab_page mm/slub.c:1870 [inline] allocate_slab mm/slub.c:2017 [inline] new_slab+0x283/0x3c0 mm/slub.c:2070 ___slab_alloc+0x979/0x1500 mm/slub.c:3223 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3322 __slab_alloc_node mm/slub.c:3375 [inline] slab_alloc_node mm/slub.c:3468 [inline] __kmem_cache_alloc_node+0x131/0x310 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0x49/0x90 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:721 [inline] _iommufd_object_alloc+0x26/0x1b0 drivers/iommu/iommufd/main.c:40 iommufd_ioas_alloc drivers/iommu/iommufd/ioas.c:27 [inline] iommufd_ioas_alloc_ioctl+0xaf/0x370 drivers/iommu/iommufd/ioas.c:46 iommufd_fops_ioctl+0x35a/0x4e0 drivers/iommu/iommufd/main.c:404 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1137 [inline] free_unref_page_prepare+0x4fa/0xaa0 mm/page_alloc.c:2347 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2487 __unfreeze_partials+0x226/0x240 mm/slub.c:2655 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x18e/0x1d0 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x65/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook mm/slab.h:763 [inline] slab_alloc_node mm/slub.c:3478 [inline] __kmem_cache_alloc_node+0x195/0x310 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0x49/0x90 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] tomoyo_realpath_from_path+0xb9/0x710 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x26f/0x450 security/tomoyo/file.c:822 security_inode_getattr+0xf1/0x150 security/security.c:2153 vfs_getattr fs/stat.c:169 [inline] vfs_fstat+0x4f/0xc0 fs/stat.c:194 vfs_fstatat+0x130/0x140 fs/stat.c:291 __do_sys_newfstatat+0x98/0x110 fs/stat.c:459 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x63/0x6b Memory state around the buggy address: ffff888079d98700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888079d98780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888079d98800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888079d98880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888079d98900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================