bisecting cause commit starting from fdd06dc6b0f832a9cd8033438cc3b01d253c3981 building syzkaller on c885789257c76ea4479ea36282f5e0a2c7861e26 testing commit fdd06dc6b0f832a9cd8033438cc3b01d253c3981 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 8043cc0881ed4dd9f1af1da7eceb4a999b6427e8310ffa6e1e6a38068bb3db08 run #0: crashed: general protection fault in kernfs_name_hash run #1: crashed: general protection fault in kernfs_name_hash run #2: crashed: general protection fault in del_gendisk run #3: crashed: general protection fault in kernfs_name_hash run #4: crashed: general protection fault in kernfs_name_hash run #5: crashed: general protection fault in del_gendisk run #6: crashed: general protection fault in kernfs_name_hash run #7: crashed: general protection fault in del_gendisk run #8: crashed: general protection fault in del_gendisk run #9: crashed: general protection fault in del_gendisk run #10: crashed: general protection fault in kernfs_name_hash run #11: crashed: general protection fault in del_gendisk run #12: crashed: general protection fault in del_gendisk run #13: crashed: general protection fault in kernfs_name_hash run #14: crashed: general protection fault in del_gendisk run #15: crashed: general protection fault in del_gendisk run #16: crashed: general protection fault in del_gendisk run #17: crashed: general protection fault in del_gendisk run #18: crashed: general protection fault in del_gendisk run #19: crashed: general protection fault in del_gendisk testing release v5.10.117 testing commit 7686a5c2a8d398196259b1bf3fa369a4fd6bcd6f compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 7df2d52b23ae1093a31984953020391f345fdbce9a9ac69b629e7e942db057d1 all runs: OK # git bisect start fdd06dc6b0f832a9cd8033438cc3b01d253c3981 7686a5c2a8d398196259b1bf3fa369a4fd6bcd6f Bisecting: 2953 revisions left to test after this (roughly 12 steps) [fd10db46d00327f730807d776db03eae98948a00] FROMGIT: kasan, mm: optimize krealloc poisoning testing commit fd10db46d00327f730807d776db03eae98948a00 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 mm/memory.c:4800:10: error: assignment of member 'vma' in read-only object mm/memory.c:4942:12: error: assignment of member 'pgoff' in read-only object mm/memory.c:4943:15: error: assignment of member 'gfp_mask' in read-only object # git bisect skip fd10db46d00327f730807d776db03eae98948a00 Bisecting: 2951 revisions left to test after this (roughly 12 steps) [9e7985701d28e10e26a8d2382a4cbd7700ea4f08] FROMGIT: arm64: kasan: simplify and inline MTE functions testing commit 9e7985701d28e10e26a8d2382a4cbd7700ea4f08 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 mm/memory.c:4800:10: error: assignment of member 'vma' in read-only object mm/memory.c:4942:12: error: assignment of member 'pgoff' in read-only object mm/memory.c:4943:15: error: assignment of member 'gfp_mask' in read-only object # git bisect skip 9e7985701d28e10e26a8d2382a4cbd7700ea4f08 Bisecting: 2951 revisions left to test after this (roughly 12 steps) [b397a0387cb280697e83033ec9a45f4a2e7bc444] ANDROID: fips140: test all implementations testing commit b397a0387cb280697e83033ec9a45f4a2e7bc444 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: cbb6cb882196cb5d77ccf785fab6fe97b9491ab21c23caf0335a90f4babf785c run #0: crashed: general protection fault in kernfs_name_hash run #1: crashed: general protection fault in del_gendisk run #2: crashed: general protection fault in del_gendisk run #3: crashed: general protection fault in kernfs_name_hash run #4: crashed: general protection fault in kernfs_name_hash run #5: crashed: general protection fault in del_gendisk run #6: crashed: general protection fault in del_gendisk run #7: crashed: general protection fault in del_gendisk run #8: crashed: general protection fault in del_gendisk run #9: crashed: general protection fault in del_gendisk # git bisect bad b397a0387cb280697e83033ec9a45f4a2e7bc444 Bisecting: 2621 revisions left to test after this (roughly 11 steps) [2a6bc198915275a36c2822d80d680922bba7ba3c] UPSTREAM: arm64: alternatives: Remove READ_ONCE() usage during patch operation testing commit 2a6bc198915275a36c2822d80d680922bba7ba3c compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: a1494a09c624a539627e52e185a90e62173b5bb5fb28c0e7091da2da1a1c073b all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip 2a6bc198915275a36c2822d80d680922bba7ba3c Bisecting: 2621 revisions left to test after this (roughly 11 steps) [79d3d549f9b3060fd78da0477c543f9e70d6e851] ANDROID: GKI: 5/7 KMI update testing commit 79d3d549f9b3060fd78da0477c543f9e70d6e851 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 2eed7c4ae4eae2e2a5f0a9326ca5bdc4a30828fb56545ef93323cda4f4506ea5 all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip 79d3d549f9b3060fd78da0477c543f9e70d6e851 Bisecting: 2621 revisions left to test after this (roughly 11 steps) [8a0e4c2b94375dcb0021c6173c3c3a4a4a8cc55a] FROMLIST: fuse: Fix crediantials leak in passthrough read_iter testing commit 8a0e4c2b94375dcb0021c6173c3c3a4a4a8cc55a compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: ddd2ac371a85f7ec80c44dde42372c04f294cb3fa907711a7d9fdbab816b7b09 all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip 8a0e4c2b94375dcb0021c6173c3c3a4a4a8cc55a Bisecting: 2621 revisions left to test after this (roughly 11 steps) [f3f8d55011837f34584fc223e2a26b13623ff296] ANDROID: sched: Add vendor hooks for update_load_avg testing commit f3f8d55011837f34584fc223e2a26b13623ff296 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 34c03ff0b0c7117c442d659ef19936ac25d7d734bf23831912358407885c5c2d all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip f3f8d55011837f34584fc223e2a26b13623ff296 Bisecting: 2621 revisions left to test after this (roughly 11 steps) [18ebdc37464a1288c3c6ca853e66efebf3e793db] ANDROID: sched: add vendor hooks for bad scheduling testing commit 18ebdc37464a1288c3c6ca853e66efebf3e793db compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 7731756aeacdb0089a301d3829053e5379af97c5f27346b088afc9d091ec3975 all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip 18ebdc37464a1288c3c6ca853e66efebf3e793db Bisecting: 2621 revisions left to test after this (roughly 11 steps) [f9761818fe9a95752e6c49f5ee5bf4640e0507db] ANDROID: GKI: Refresh ABI following trimmed symbol CRC fix testing commit f9761818fe9a95752e6c49f5ee5bf4640e0507db compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: e3ba0a64c5a221919a5389cae0222d6b85d77a00937a07b5cd62d13b7f64f031 all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip f9761818fe9a95752e6c49f5ee5bf4640e0507db Bisecting: 2621 revisions left to test after this (roughly 11 steps) [1c2af92b869c363ada8df84340bab033b81e6628] UPSTREAM: psci: Support psci_ops.get_version for v0.1 testing commit 1c2af92b869c363ada8df84340bab033b81e6628 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 019eea22f2d7dcd1debe1a3f2a1be98e9b412234f444cdde919d51f28ee79267 all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip 1c2af92b869c363ada8df84340bab033b81e6628 Bisecting: 2621 revisions left to test after this (roughly 11 steps) [73372c9835b2de23dedd57892fcc0c971d97fedf] ANDROID: scsi: ufs: add UFSHCD_QUIRK_NO_KEYSLOTS testing commit 73372c9835b2de23dedd57892fcc0c971d97fedf compiler: gcc (GCC) 8.4.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: a914129c56b8dec2b652c0e1c2c8936b20600a25cdcabfda0e4f2488024e6979 all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip 73372c9835b2de23dedd57892fcc0c971d97fedf Bisecting: 2621 revisions left to test after this (roughly 11 steps) [2dc1df560308a1882143693b64c4f893d75f8d94] UPSTREAM: xhci: use xhci_td_cleanup() helper when giving back cancelled URBs testing commit 2dc1df560308a1882143693b64c4f893d75f8d94 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 4d347d9e5157ff418de79f7eb1de9fc3c8f71f05a8159ab3ae40805189adf3b0 all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip 2dc1df560308a1882143693b64c4f893d75f8d94 Bisecting: 2621 revisions left to test after this (roughly 11 steps) [a428f6d3cdab8091c39c7145e6f8bbb03b22693f] FROMGIT: drm/virtio: Fix use after free in get_capset_info callback. testing commit a428f6d3cdab8091c39c7145e6f8bbb03b22693f compiler: gcc (GCC) 8.4.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 03fda11a969f3f1b2334b41f6e1a373f4fb5f9cd508162a13b0eba2d57f4f6df all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip a428f6d3cdab8091c39c7145e6f8bbb03b22693f Bisecting: 2621 revisions left to test after this (roughly 11 steps) [2a492c11b930f14c1f69d5aacd70146c0938756a] UPSTREAM: xhci: prevent a theoretical endless loop while preparing rings. testing commit 2a492c11b930f14c1f69d5aacd70146c0938756a compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 889b0ef5b52da419d7f9585bf31baa215a3f6bf1fef61708489a75962726918d all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip 2a492c11b930f14c1f69d5aacd70146c0938756a Bisecting: 2621 revisions left to test after this (roughly 11 steps) [836219141ff7a77e7fab0bd749edd746fd36fef2] Revert "iov_iter: transparently handle compat iovecs in import_iovec" testing commit 836219141ff7a77e7fab0bd749edd746fd36fef2 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 47fb4fc31bcbaae07481068b4b20a53540cd02ecdede7a5d5fc2f1d25ec803f2 all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip 836219141ff7a77e7fab0bd749edd746fd36fef2 Bisecting: 2621 revisions left to test after this (roughly 11 steps) [d4091df63c80ad87e4c3256d13405730da54bdc7] ANDROID: GKI: Update symbols list for vivo testing commit d4091df63c80ad87e4c3256d13405730da54bdc7 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 1a586df0fa7d054f1fa87e1ea9fd3d66fb1c3a4a9f88ac50ac6977c85d7a1083 run #0: crashed: general protection fault in kernfs_name_hash run #1: crashed: general protection fault in kernfs_name_hash run #2: crashed: general protection fault in kernfs_name_hash run #3: crashed: general protection fault in del_gendisk run #4: crashed: general protection fault in del_gendisk run #5: crashed: general protection fault in kernfs_name_hash run #6: crashed: general protection fault in del_gendisk run #7: crashed: general protection fault in del_gendisk run #8: crashed: general protection fault in del_gendisk run #9: crashed: general protection fault in del_gendisk # git bisect bad d4091df63c80ad87e4c3256d13405730da54bdc7 Bisecting: 2616 revisions left to test after this (roughly 11 steps) [d728c7f91b31139eeb94604f465fe51b5aedc84d] FROMLIST: kbuild: improve libelf detection testing commit d728c7f91b31139eeb94604f465fe51b5aedc84d compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 87a09efef82f0cad27ef2e0d13f985768fecf29d0fe2040e75ab18a23f02e847 all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip d728c7f91b31139eeb94604f465fe51b5aedc84d Bisecting: 2616 revisions left to test after this (roughly 11 steps) [b011ee0886ae3b5184cfd119c03c379a161a87b1] ANDROID: softirq: Export irq_handler_exit tracepoint testing commit b011ee0886ae3b5184cfd119c03c379a161a87b1 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 14df2c229c7241f1d8d2736fd74b4731947c1acfd4310ef9b29701d179ec328d all runs: basic kernel testing failed: KASAN: use-after-free Read in task_active_pid_ns # git bisect skip b011ee0886ae3b5184cfd119c03c379a161a87b1 Bisecting: 2616 revisions left to test after this (roughly 11 steps) [f9fcdaeab7006daef51a87b61801264805a7a729] ANDROID: sched: remove regular vendor hooks for 32bit execve testing commit f9fcdaeab7006daef51a87b61801264805a7a729 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 1b9a3f3f8f31923e383762d5c5f9dd4d94bb312b676d8d6e18f1cbb0e4602544 all runs: OK # git bisect good f9fcdaeab7006daef51a87b61801264805a7a729 Bisecting: 281 revisions left to test after this (roughly 8 steps) [60a4c35570d985cd1e1304fcbd31e4df79d07d6e] ANDROID: xt_quota2: clear quota2_log message before sending testing commit 60a4c35570d985cd1e1304fcbd31e4df79d07d6e compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: f6c6c8279d2da7c8d5b80d8301db759f2192e240840c930aa9f3175159701629 run #0: crashed: general protection fault in kernfs_name_hash run #1: crashed: general protection fault in del_gendisk run #2: crashed: general protection fault in kernfs_name_hash run #3: crashed: general protection fault in kernfs_name_hash run #4: crashed: general protection fault in del_gendisk run #5: crashed: general protection fault in del_gendisk run #6: crashed: general protection fault in kernfs_name_hash run #7: crashed: general protection fault in kernfs_name_hash run #8: crashed: general protection fault in kernfs_name_hash run #9: crashed: general protection fault in del_gendisk # git bisect bad 60a4c35570d985cd1e1304fcbd31e4df79d07d6e Bisecting: 139 revisions left to test after this (roughly 7 steps) [194fd9239ae697974aad9e038d4aea509bf45c43] ANDROID: GKI: fscrypt: add ABI padding to struct fscrypt_operations testing commit 194fd9239ae697974aad9e038d4aea509bf45c43 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 828cf31c1a1707eb2f7afd35090bcb1b4ef64fcb94f8ca8b0b5c8aaa7a73e26f all runs: OK # git bisect good 194fd9239ae697974aad9e038d4aea509bf45c43 Bisecting: 69 revisions left to test after this (roughly 6 steps) [e30728e4ff6f4ae77cf89547d5f1df3bddb0d1f6] ANDROID: ABI: initial update allowed list for galaxy testing commit e30728e4ff6f4ae77cf89547d5f1df3bddb0d1f6 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: b9bafaf0fe463f4a6d7c9ab2aa6d71f3cc04be3ec0aacfc3f7e609144b7676d8 all runs: OK # git bisect good e30728e4ff6f4ae77cf89547d5f1df3bddb0d1f6 Bisecting: 34 revisions left to test after this (roughly 5 steps) [bda49ad0602e5250a9d3dd61deda19d3e5615c54] FROMGIT: loop: Select I/O scheduler 'none' from inside add_disk() testing commit bda49ad0602e5250a9d3dd61deda19d3e5615c54 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 9270af136efe22f6357056c0ee098cf3929eb9609c6388f8abefc3a27ddcaa1f run #0: crashed: general protection fault in del_gendisk run #1: crashed: general protection fault in del_gendisk run #2: crashed: general protection fault in del_gendisk run #3: crashed: general protection fault in kernfs_name_hash run #4: crashed: general protection fault in kernfs_name_hash run #5: crashed: general protection fault in kernfs_name_hash run #6: crashed: general protection fault in kernfs_name_hash run #7: crashed: general protection fault in del_gendisk run #8: crashed: general protection fault in kernfs_name_hash run #9: crashed: general protection fault in kernfs_name_hash # git bisect bad bda49ad0602e5250a9d3dd61deda19d3e5615c54 Bisecting: 16 revisions left to test after this (roughly 4 steps) [36fbb55631563638f7a5e6d53168361618c5c168] FROMGIT: procfs: prevent unpriveleged processes accessing fdinfo dir testing commit 36fbb55631563638f7a5e6d53168361618c5c168 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: f6e8f645ef2ae8e7a0482098b8f6aaaf1db0720f88b1662fa65cd07bf28f29b2 run #0: basic kernel testing failed: timed out run #1: OK run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect good 36fbb55631563638f7a5e6d53168361618c5c168 Bisecting: 8 revisions left to test after this (roughly 3 steps) [045204b0801f06ac45b9931cffed155624b1ae55] FROMGIT: KVM: arm64: Unregister HYP sections from kmemleak in protected mode testing commit 045204b0801f06ac45b9931cffed155624b1ae55 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: cc6acafbdd36e58d8a9792bc51ca6694cc45d58c9dfc955489b174a87422ec92 all runs: OK # git bisect good 045204b0801f06ac45b9931cffed155624b1ae55 Bisecting: 3 revisions left to test after this (roughly 2 steps) [41b79ac98d5dc5469e47488a5f095116cf2dbe7c] FROMGIT: usb: dwc3: gadget: Use list_replace_init() before traversing lists testing commit 41b79ac98d5dc5469e47488a5f095116cf2dbe7c compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 164583cfec87b4c92109646782198c2e26d3539e9686c502a67f978942790134 all runs: OK # git bisect good 41b79ac98d5dc5469e47488a5f095116cf2dbe7c Bisecting: 1 revision left to test after this (roughly 1 step) [8914725a582861666a2a298efbcb5ae7613a47b7] FROMGIT: usb: typec: tcpm: Keep other events when receiving FRS and Sourcing_vbus events testing commit 8914725a582861666a2a298efbcb5ae7613a47b7 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 19cc471a612a10fb2799dd99ac4336b53632e22abf2a383699b4209a478a04fd all runs: OK # git bisect good 8914725a582861666a2a298efbcb5ae7613a47b7 Bisecting: 0 revisions left to test after this (roughly 0 steps) [d8b946254effbe36780f0b855da509a07470b8d2] FROMGIT: blk-mq: Introduce the BLK_MQ_F_NO_SCHED_BY_DEFAULT flag testing commit d8b946254effbe36780f0b855da509a07470b8d2 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 7b45c0fc6c60504de5c0d70aa485ac2956f70b5d45cee1fafcf0f9bc2767effa all runs: OK # git bisect good d8b946254effbe36780f0b855da509a07470b8d2 bda49ad0602e5250a9d3dd61deda19d3e5615c54 is the first bad commit commit bda49ad0602e5250a9d3dd61deda19d3e5615c54 Author: Bart Van Assche Date: Mon Aug 2 10:05:29 2021 -0700 FROMGIT: loop: Select I/O scheduler 'none' from inside add_disk() We noticed that the user interface of Android devices becomes very slow under memory pressure. This is because Android uses the zram driver on top of the loop driver for swapping, because under memory pressure the swap code alternates reads and writes quickly, because mq-deadline is the default scheduler for loop devices and because mq-deadline delays writes by five seconds for such a workload with default settings. Fix this by making the kernel select I/O scheduler 'none' from inside add_disk() for loop devices. This default can be overridden at any time from user space, e.g. via a udev rule. This approach has an advantage compared to changing the I/O scheduler from userspace from 'mq-deadline' into 'none', namely that synchronize_rcu() does not get called. Additionally, this patch reduces the Android boot time on my test setup with 0.5 seconds compared to configuring the loop I/O scheduler from user space. Signed-off-by: Bart Van Assche Bug: 194450129 (cherry picked from commit 2112f5c1330a671fa852051d85cb9eadc05d7eb7 git://git.kernel.dk/linux-block/ for-5.15/block) Change-Id: I6f9579b4cd2cb22fcb5c858d4f292f1870336fdd Signed-off-by: Bart Van Assche drivers/block/loop.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) culprit signature: 9270af136efe22f6357056c0ee098cf3929eb9609c6388f8abefc3a27ddcaa1f parent signature: 7b45c0fc6c60504de5c0d70aa485ac2956f70b5d45cee1fafcf0f9bc2767effa revisions tested: 28, total time: 5h11m1.229977252s (build: 2h45m35.386596299s, test: 2h20m10.144660625s) first bad commit: bda49ad0602e5250a9d3dd61deda19d3e5615c54 FROMGIT: loop: Select I/O scheduler 'none' from inside add_disk() recipients (to): ["axboe@kernel.dk" "bvanassche@acm.org" "bvanassche@google.com" "linux-block@vger.kernel.org"] recipients (cc): ["linux-kernel@vger.kernel.org"] crash: general protection fault in kernfs_name_hash RSP: 002b:00007f482fcc2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f482fe5ef60 RCX: 00007f482fd4c109 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 RBP: 00007f482fda608d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc32454e5f R14: 00007f482fcc2300 R15: 0000000000022000 ---[ end trace d302474f4529ceb4 ]--- general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 421 Comm: syz-executor.0 Tainted: G W 5.10.43-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:strlen+0x1f/0xa0 lib/string.c:568 Code: 48 8b 45 e8 eb 88 0f 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 fa 48 89 e5 48 c1 ea 03 41 54 49 89 fc 53 48 83 ec 08 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 4d 41 80 3c 24 RSP: 0018:ffffc90000907c90 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff84262aa9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000907ca8 R08: 0000000000000001 R09: ffffc90000907cbf R10: fffff52000120f97 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000008 FS: 00007f482fcc2700(0000) GS:ffff8881f7200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f482fe5f028 CR3: 000000010d6e7000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kernfs_name_hash+0x16/0xc0 fs/kernfs/dir.c:302 kernfs_find_ns+0x84/0x210 fs/kernfs/dir.c:841 kernfs_remove_by_name_ns+0x32/0x80 fs/kernfs/dir.c:1514 kernfs_remove_by_name include/linux/kernfs.h:608 [inline] sysfs_remove_link+0x37/0xa0 fs/sysfs/symlink.c:152 del_gendisk+0x5f8/0xa60 block/genhd.c:951 loop_remove drivers/block/loop.c:2194 [inline] loop_control_ioctl drivers/block/loop.c:2293 [inline] loop_control_ioctl+0x30d/0x3d0 drivers/block/loop.c:2259 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x129/0x1a0 fs/ioctl.c:739 do_syscall_64+0x32/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f482fd4c109 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f482fcc2168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f482fe5ef60 RCX: 00007f482fd4c109 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 RBP: 00007f482fda608d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc32454e5f R14: 00007f482fcc2300 R15: 0000000000022000 Modules linked in: ---[ end trace d302474f4529ceb5 ]--- RIP: 0010:strlen+0x1f/0xa0 lib/string.c:568 Code: 48 8b 45 e8 eb 88 0f 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 fa 48 89 e5 48 c1 ea 03 41 54 49 89 fc 53 48 83 ec 08 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 4d 41 80 3c 24 RSP: 0018:ffffc90000907c90 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff84262aa9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000907ca8 R08: 0000000000000001 R09: ffffc90000907cbf R10: fffff52000120f97 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000008 FS: 00007f482fcc2700(0000) GS:ffff8881f7200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f482fe5f028 CR3: 000000010d6e7000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 48 8b 45 e8 mov -0x18(%rbp),%rax 4: eb 88 jmp 0xffffff8e 6: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) b: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 12: fc ff df 15: 55 push %rbp 16: 48 89 fa mov %rdi,%rdx 19: 48 89 e5 mov %rsp,%rbp 1c: 48 c1 ea 03 shr $0x3,%rdx 20: 41 54 push %r12 22: 49 89 fc mov %rdi,%r12 25: 53 push %rbx 26: 48 83 ec 08 sub $0x8,%rsp * 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction 2e: 48 89 fa mov %rdi,%rdx 31: 83 e2 07 and $0x7,%edx 34: 38 d0 cmp %dl,%al 36: 7f 04 jg 0x3c 38: 84 c0 test %al,%al 3a: 75 4d jne 0x89 3c: 41 rex.B 3d: 80 .byte 0x80 3e: 3c 24 cmp $0x24,%al