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BUG: KASAN: slab-use-after-free in ucma_create_uevent+0xb60/0xbe0 drivers/infiniband/core/ucma.c:275
Read of size 8 at addr ffff88803543e710 by task kworker/u32:7/216

CPU: 1 UID: 0 PID: 216 Comm: kworker/u32:7 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: rdma_cm cma_iboe_join_work_handler
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595
 ucma_create_uevent+0xb60/0xbe0 drivers/infiniband/core/ucma.c:275
 ucma_event_handler+0x102/0x940 drivers/infiniband/core/ucma.c:356
 cma_cm_event_handler+0x9b/0x320 drivers/infiniband/core/cma.c:2181
 cma_iboe_join_work_handler+0xca/0x180 drivers/infiniband/core/cma.c:3017
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
 process_scheduled_works kernel/workqueue.c:3385 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 6237:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 ucma_process_join+0x232/0xa20 drivers/infiniband/core/ucma.c:1532
 ucma_join_multicast+0xe9/0x160 drivers/infiniband/core/ucma.c:1624
 ucma_write+0x1fb/0x330 drivers/infiniband/core/ucma.c:1856
 vfs_write+0x2aa/0x1070 fs/read_write.c:686
 ksys_write+0x1f8/0x250 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6237:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6250 [inline]
 kfree+0x223/0x6c0 mm/slub.c:6565
 ucma_process_join+0x39a/0xa20 drivers/infiniband/core/ucma.c:1583
 ucma_join_multicast+0xe9/0x160 drivers/infiniband/core/ucma.c:1624
 ucma_write+0x1fb/0x330 drivers/infiniband/core/ucma.c:1856
 vfs_write+0x2aa/0x1070 fs/read_write.c:686
 ksys_write+0x1f8/0x250 fs/read_write.c:740
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88803543e700
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 16 bytes inside of
 freed 192-byte region [ffff88803543e700, ffff88803543e7c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3543e
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801b8423c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 21540936186, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858
 prep_new_page mm/page_alloc.c:1866 [inline]
 get_page_from_freelist+0x11a6/0x33b0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x27c/0x2bc0 mm/page_alloc.c:5226
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab mm/slub.c:3467 [inline]
 new_slab+0xa6/0x6c0 mm/slub.c:3525
 refill_objects+0x277/0x420 mm/slub.c:7255
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 __kmalloc_cache_noprof+0x493/0x6f0 mm/slub.c:5414
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 call_usermodehelper_setup+0xaf/0x360 kernel/umh.c:362
 kobject_uevent_env+0x17c1/0x18b0 lib/kobject_uevent.c:631
 driver_register+0x29c/0x360 drivers/base/driver.c:257
 do_one_initcall+0x121/0x750 init/main.c:1392
 do_initcall_level init/main.c:1454 [inline]
 do_initcalls init/main.c:1470 [inline]
 do_basic_setup init/main.c:1490 [inline]
 kernel_init_freeable+0x6ea/0x7b0 init/main.c:1703
 kernel_init+0x1f/0x1e0 init/main.c:1593
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88803543e600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88803543e680: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88803543e700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88803543e780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88803543e800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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