bisecting cause commit starting from 93717cde744f9d26aa1b4561f7d9ba2a230459eb
building syzkaller on 8f58a0efbf867526a0adee8d9a5cb38e2ebf1ee4
testing commit 93717cde744f9d26aa1b4561f7d9ba2a230459eb
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: ff90362e05b0305b1559ef8a2060dfb6e2a17fcb325009c13f52840b435325c6
run #0: crashed: KASAN: use-after-free Read in __d_alloc
run #1: crashed: KASAN: use-after-free Read in __d_alloc
run #2: crashed: KASAN: use-after-free Read in __d_alloc
run #3: crashed: KASAN: use-after-free Read in __d_alloc
run #4: crashed: KASAN: use-after-free Read in __d_alloc
run #5: crashed: KASAN: use-after-free Read in __d_alloc
run #6: boot failed: KFENCE: use-after-free in kvm_fastop_exception
run #7: crashed: KASAN: use-after-free Read in __d_alloc
run #8: crashed: KASAN: use-after-free Read in __d_alloc
run #9: crashed: KASAN: use-after-free Read in __d_alloc
run #10: crashed: KASAN: use-after-free Read in __d_alloc
run #11: crashed: KASAN: use-after-free Read in __d_alloc
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: crashed: KASAN: use-after-free Read in __d_alloc
run #17: OK
run #18: OK
run #19: OK
testing release v5.14
testing commit 7d2a07b769330c34b4deabeed939325c77a7ec2f
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 92e7ebdbf2fb523cffb3c9b265055e5b0deccc61334a1c71eee4b4a23f798170
all runs: OK
# git bisect start 93717cde744f9d26aa1b4561f7d9ba2a230459eb 7d2a07b769330c34b4deabeed939325c77a7ec2f
Bisecting: 5534 revisions left to test after this (roughly 13 steps)
[72746889fb1f642a7594fd2e22f40d48b608d199] Merge remote-tracking branch 'net-next/master'

testing commit 72746889fb1f642a7594fd2e22f40d48b608d199
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 68e6c02cde785fb0f59d2ef3b98adfb2c74d5ee7fcbbf40e40a0b206b8f72e63
all runs: OK
# git bisect good 72746889fb1f642a7594fd2e22f40d48b608d199
Bisecting: 2725 revisions left to test after this (roughly 12 steps)
[c9708de376bac57442e369cd99e530c939e2793f] Merge remote-tracking branch 'iommu/next'

testing commit c9708de376bac57442e369cd99e530c939e2793f
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 53911184bffa646f533c7469f01aed1afaf85816b73f3c60c61f83601483a1bc
run #0: basic kernel testing failed: KFENCE: use-after-free in kvm_fastop_exception
run #1: crashed: KASAN: use-after-free Read in __d_alloc
run #2: crashed: KASAN: use-after-free Read in __d_alloc
run #3: crashed: KASAN: use-after-free Read in __d_alloc
run #4: crashed: KASAN: use-after-free Read in __d_alloc
run #5: crashed: KASAN: use-after-free Read in __d_alloc
run #6: crashed: KASAN: use-after-free Read in __d_alloc
run #7: crashed: KASAN: use-after-free Read in __d_alloc
run #8: OK
run #9: OK
# git bisect bad c9708de376bac57442e369cd99e530c939e2793f
Bisecting: 1449 revisions left to test after this (roughly 11 steps)
[8f0284f190e6a0aa09015090568c03f18288231a] Merge tag 'amd-drm-next-5.15-2021-08-27' of https://gitlab.freedesktop.org/agd5f/linux into drm-next

testing commit 8f0284f190e6a0aa09015090568c03f18288231a
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: d6db902119ab92e8699d79b18cbd792bbff8850f5de59430af2a4a3585258e69
all runs: OK
# git bisect good 8f0284f190e6a0aa09015090568c03f18288231a
Bisecting: 676 revisions left to test after this (roughly 10 steps)
[d9736b76d05e8ac716f75bea874ed16cc2cb9c9c] Merge remote-tracking branch 'sound-asoc/for-next'

testing commit d9736b76d05e8ac716f75bea874ed16cc2cb9c9c
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 39c3a656458d4f8a439b31152f2dcfbe0703d300965662fed49576d3cd02d467
all runs: OK
# git bisect good d9736b76d05e8ac716f75bea874ed16cc2cb9c9c
Bisecting: 330 revisions left to test after this (roughly 8 steps)
[24fddd21936e104d6a106a8893cf1ffbf90c93fc] Merge remote-tracking branch 'device-mapper/for-next'

testing commit 24fddd21936e104d6a106a8893cf1ffbf90c93fc
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 4c0721c2544a5969c867b0e3bc19025e5d777d5eb97561b9f8ae1cff1ad8ca85
run #0: crashed: KASAN: use-after-free Read in __d_alloc
run #1: crashed: KASAN: use-after-free Read in __d_alloc
run #2: crashed: KASAN: use-after-free Read in __d_alloc
run #3: crashed: KASAN: use-after-free Read in __d_alloc
run #4: crashed: KASAN: use-after-free Read in __d_alloc
run #5: crashed: KASAN: use-after-free Read in __d_alloc
run #6: crashed: KASAN: use-after-free Read in __d_alloc
run #7: crashed: KASAN: use-after-free Read in __d_alloc
run #8: OK
run #9: OK
# git bisect bad 24fddd21936e104d6a106a8893cf1ffbf90c93fc
Bisecting: 182 revisions left to test after this (roughly 8 steps)
[a85e409100f51ea5d4a3b3929daee28082d14a20] Merge branch 'for-5.15/libata' into for-next

testing commit a85e409100f51ea5d4a3b3929daee28082d14a20
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: aa937ea172a20e6f5f4e718ec0152d3923c85932c6ab04eb2990e941fef9e61e
all runs: OK
# git bisect good a85e409100f51ea5d4a3b3929daee28082d14a20
Bisecting: 95 revisions left to test after this (roughly 7 steps)
[b10a0cf751124712be6f1e1a4103480c239a5073] Merge branch 'for-5.15/io_uring-vfs' into for-next

testing commit b10a0cf751124712be6f1e1a4103480c239a5073
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 4209b72f7cc32255b9dfab057edc499c296cae6b935f42c53414a44061f73b05
run #0: OK
run #1: OK
run #2: OK
run #3: OK
run #4: crashed: KFENCE: use-after-free in kvm_fastop_exception
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
reproducer seems to be flaky
# git bisect bad b10a0cf751124712be6f1e1a4103480c239a5073
Bisecting: 43 revisions left to test after this (roughly 6 steps)
[41a5169c23ebe85fdd0b64a0b6381f486a34ef3c] io_uring: code clean for completion_lock in io_arm_poll_handler()

testing commit 41a5169c23ebe85fdd0b64a0b6381f486a34ef3c
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 82be70af1435ff5418750c51d9a73a776c74520bf3ecb66cbb9704f28293638a
all runs: OK
# git bisect good 41a5169c23ebe85fdd0b64a0b6381f486a34ef3c
Bisecting: 21 revisions left to test after this (roughly 5 steps)
[2c5d763c1939fbd130452ee0d4d1a44b5dd97bb7] io_uring: add clarifying comment for io_cqring_ev_posted()

testing commit 2c5d763c1939fbd130452ee0d4d1a44b5dd97bb7
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 52b21340b1a326cd63d3e86fbbd14cf432ab6f26736c3a6142ff9993eda4519d
all runs: OK
# git bisect good 2c5d763c1939fbd130452ee0d4d1a44b5dd97bb7
Bisecting: 10 revisions left to test after this (roughly 4 steps)
[7a8721f84fcb3b2946a92380b6fc311e017ff02c] io_uring: add support for IORING_OP_SYMLINKAT

testing commit 7a8721f84fcb3b2946a92380b6fc311e017ff02c
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 0d2d1ef66deb93f341bd05c38953f872fc5bbe3d6f5495bda296e882fa3e5ca2
run #0: crashed: KASAN: use-after-free Read in __d_alloc
run #1: crashed: KASAN: use-after-free Read in __d_alloc
run #2: crashed: KASAN: use-after-free Read in __d_alloc
run #3: crashed: KASAN: use-after-free Read in __d_alloc
run #4: crashed: KASAN: use-after-free Read in __d_alloc
run #5: crashed: KASAN: use-after-free Read in __d_alloc
run #6: crashed: KASAN: use-after-free Read in __d_alloc
run #7: crashed: KFENCE: use-after-free in __d_alloc
run #8: crashed: KASAN: use-after-free Read in __d_alloc
run #9: crashed: KASAN: use-after-free Read in __d_alloc
run #10: crashed: KASAN: use-after-free Read in __d_alloc
run #11: crashed: KASAN: use-after-free Read in __d_alloc
run #12: boot failed: KFENCE: use-after-free in kvm_fastop_exception
run #13: crashed: KASAN: use-after-free Read in __d_alloc
run #14: crashed: KASAN: use-after-free Read in __d_alloc
run #15: crashed: KASAN: use-after-free Read in __d_alloc
run #16: OK
run #17: OK
run #18: OK
run #19: OK
# git bisect bad 7a8721f84fcb3b2946a92380b6fc311e017ff02c
Bisecting: 5 revisions left to test after this (roughly 3 steps)
[7797251bb5ab7f184dafdfebd05f469ff6a67b77] namei: make do_mknodat() take struct filename

testing commit 7797251bb5ab7f184dafdfebd05f469ff6a67b77
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 18aaa0772b09943d5fed1feed38956c68b30ad13140122fb853147604d2172e8
run #0: crashed: KASAN: use-after-free Read in __d_alloc
run #1: crashed: KASAN: use-after-free Read in __d_alloc
run #2: crashed: KASAN: use-after-free Read in __d_alloc
run #3: crashed: KASAN: use-after-free Read in __d_alloc
run #4: crashed: KASAN: use-after-free Read in __d_alloc
run #5: crashed: KASAN: use-after-free Read in __d_alloc
run #6: crashed: KASAN: use-after-free Read in __d_alloc
run #7: crashed: KASAN: use-after-free Read in __d_alloc
run #8: crashed: KFENCE: use-after-free in kvm_fastop_exception
run #9: crashed: KASAN: use-after-free Read in __d_alloc
run #10: crashed: KASAN: use-after-free Read in __d_alloc
run #11: crashed: KASAN: use-after-free Read in __d_alloc
run #12: crashed: KASAN: use-after-free Read in __d_alloc
run #13: crashed: KASAN: use-after-free Read in __d_alloc
run #14: crashed: KASAN: use-after-free Read in __d_alloc
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
# git bisect bad 7797251bb5ab7f184dafdfebd05f469ff6a67b77
Bisecting: 2 revisions left to test after this (roughly 1 step)
[91ef658fb8b82837f94ea0d45d14b5b2d2541e70] namei: ignore ERR/NULL names in putname()

testing commit 91ef658fb8b82837f94ea0d45d14b5b2d2541e70
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: ec636febeb079819198cd2b6115c3b7476f5c42457e0566916309931054d25dc
all runs: OK
# git bisect good 91ef658fb8b82837f94ea0d45d14b5b2d2541e70
Bisecting: 0 revisions left to test after this (roughly 1 step)
[584d3226d665214dc1c498045c253529acdd3134] namei: make do_mkdirat() take struct filename

testing commit 584d3226d665214dc1c498045c253529acdd3134
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 34a03c5558c5ff5cb2347504f9d87613c1af113a68505803ab39d9030c17e978
run #0: crashed: KASAN: use-after-free Read in __d_alloc
run #1: crashed: KASAN: use-after-free Read in __d_alloc
run #2: crashed: KASAN: use-after-free Read in __d_alloc
run #3: crashed: KASAN: use-after-free Read in __d_alloc
run #4: crashed: KASAN: use-after-free Read in __d_alloc
run #5: crashed: KASAN: use-after-free Read in __d_alloc
run #6: crashed: KASAN: use-after-free Read in __d_alloc
run #7: crashed: KASAN: use-after-free Read in __d_alloc
run #8: crashed: KASAN: use-after-free Read in __d_alloc
run #9: crashed: KASAN: use-after-free Read in __d_alloc
run #10: crashed: KASAN: use-after-free Read in __d_alloc
run #11: crashed: KASAN: use-after-free Read in __d_alloc
run #12: crashed: KASAN: use-after-free Read in __d_alloc
run #13: OK
run #14: OK
run #15: crashed: KASAN: use-after-free Read in __d_alloc
run #16: OK
run #17: OK
run #18: crashed: KASAN: use-after-free Read in __d_alloc
run #19: OK
# git bisect bad 584d3226d665214dc1c498045c253529acdd3134
Bisecting: 0 revisions left to test after this (roughly 0 steps)
[0ee50b47532a81ab36046241822d1ecb4e08e76d] namei: change filename_parentat() calling conventions

testing commit 0ee50b47532a81ab36046241822d1ecb4e08e76d
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 9538a4aca7b4f41b2c803e64f89403b8ceeeec85a676da80f94d3888ac911f45
all runs: boot failed: KASAN: use-after-free Read in __d_alloc
# git bisect skip 0ee50b47532a81ab36046241822d1ecb4e08e76d
There are only 'skip'ped commits left to test.
The first bad commit could be any of:
0ee50b47532a81ab36046241822d1ecb4e08e76d
584d3226d665214dc1c498045c253529acdd3134
We cannot bisect more!

Reproducer flagged being flaky
revisions tested: 16, total time: 4h56m54.017462898s (build: 1h50m49.167833001s, test: 3h4m20.136244118s)
bisection is inconclusive, the first bad commit could be any of:
0ee50b47532a81ab36046241822d1ecb4e08e76d
584d3226d665214dc1c498045c253529acdd3134