RDX: 000000002001cf83 RSI: 0000000000000000 RDI: 0000000020b24000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ================================================================== BUG: KASAN: use-after-free in mpi_free+0x117/0x150 lib/mpi/mpiutil.c:114 Read of size 4 at addr ffff8801d9660d50 by task syz-executor4/4249 CPU: 1 PID: 4249 Comm: syz-executor4 Not tainted 4.14.0+ #85 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 mpi_free+0x117/0x150 lib/mpi/mpiutil.c:114 dh_clear_params crypto/dh.c:26 [inline] dh_free_ctx crypto/dh.c:34 [inline] dh_exit_tfm+0x3d/0x140 crypto/dh.c:161 crypto_kpp_exit_tfm+0x52/0x70 crypto/kpp.c:63 crypto_exit_ops crypto/api.c:314 [inline] crypto_destroy_tfm+0xb9/0x2e0 crypto/api.c:578 crypto_free_kpp include/crypto/kpp.h:165 [inline] __keyctl_dh_compute+0xffa/0x1970 security/keys/dh.c:412 compat_keyctl_dh_compute+0x2bb/0x3e0 security/keys/compat_dh.c:39 C_SYSC_keyctl security/keys/compat.c:136 [inline] compat_SyS_keyctl+0x72/0x2c0 security/keys/compat.c:59 do_syscall_32_irqs_on arch/x86/entry/common.c:329 [inline] do_fast_syscall_32+0x3f2/0xf05 arch/x86/entry/common.c:391 entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125 RIP: 0023:0xf7f2cc79 RSP: 002b:00000000f772801c EFLAGS: 00000296 ORIG_RAX: 0000000000000120 RAX: ffffffffffffffda RBX: 0000000000000017 RCX: 000000002000dff4 RDX: 000000002001cf83 RSI: 0000000000000000 RDI: 0000000020b24000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 4249: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3628 kmalloc include/linux/slab.h:494 [inline] mpi_alloc+0x4b/0x230 lib/mpi/mpiutil.c:34 mpi_read_raw_data+0x1e5/0x440 lib/mpi/mpicoder.c:57 dh_set_params crypto/dh.c:69 [inline] dh_set_secret+0x257/0x600 crypto/dh.c:94 crypto_kpp_set_secret include/crypto/kpp.h:291 [inline] __keyctl_dh_compute+0x99b/0x1970 security/keys/dh.c:333 compat_keyctl_dh_compute+0x2bb/0x3e0 security/keys/compat_dh.c:39 C_SYSC_keyctl security/keys/compat.c:136 [inline] compat_SyS_keyctl+0x72/0x2c0 security/keys/compat.c:59 do_syscall_32_irqs_on arch/x86/entry/common.c:329 [inline] do_fast_syscall_32+0x3f2/0xf05 arch/x86/entry/common.c:391 entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125 Freed by task 4249: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3504 [inline] kfree+0xca/0x250 mm/slab.c:3821 mpi_free+0xcb/0x150 lib/mpi/mpiutil.c:121 dh_set_params crypto/dh.c:75 [inline] dh_set_secret+0x3e5/0x600 crypto/dh.c:94 crypto_kpp_set_secret include/crypto/kpp.h:291 [inline] __keyctl_dh_compute+0x99b/0x1970 security/keys/dh.c:333 compat_keyctl_dh_compute+0x2bb/0x3e0 security/keys/compat_dh.c:39 C_SYSC_keyctl security/keys/compat.c:136 [inline] compat_SyS_keyctl+0x72/0x2c0 security/keys/compat.c:59 do_syscall_32_irqs_on arch/x86/entry/common.c:329 [inline] do_fast_syscall_32+0x3f2/0xf05 arch/x86/entry/common.c:391 entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125 The buggy address belongs to the object at ffff8801d9660d40 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 16 bytes inside of 32-byte region [ffff8801d9660d40, ffff8801d9660d60) The buggy address belongs to the page: page:ffffea0007659800 count:1 mapcount:0 mapping:ffff8801d9660000 index:0xffff8801d9660fc1 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801d9660000 ffff8801d9660fc1 000000010000003f raw: ffff8801dac01248 ffffea00075b51e0 ffff8801dac001c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d9660c00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8801d9660c80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc >ffff8801d9660d00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ^ ffff8801d9660d80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8801d9660e00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ==================================================================