bisecting cause commit starting from 2f7b98d1e55ccd34e4998bf5f321ec7b9d6b451b
building syzkaller on 7e2b734bac96c22086fedd1b18135da06d5e4054
testing commit 2f7b98d1e55ccd34e4998bf5f321ec7b9d6b451b with gcc (GCC) 10.2.1 20210217
kernel signature: 6dcedb5559249ae466c589a7b7366855521d1993d96746d872cbe8313cee7ba8
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: KASAN: use-after-free Write in ext4_put_super
run #2: crashed: KASAN: use-after-free Write in ext4_put_super
run #3: crashed: KASAN: use-after-free Write in ext4_put_super
run #4: crashed: KASAN: use-after-free Write in ext4_put_super
run #5: crashed: KASAN: use-after-free Write in ext4_put_super
run #6: crashed: KASAN: use-after-free Write in ext4_put_super
run #7: crashed: KASAN: use-after-free Write in ext4_put_super
run #8: crashed: KASAN: use-after-free Write in ext4_put_super
run #9: crashed: KASAN: use-after-free Write in ext4_put_super
run #10: crashed: KASAN: use-after-free Write in ext4_put_super
run #11: crashed: KASAN: use-after-free Write in ext4_put_super
run #12: crashed: KASAN: use-after-free Write in ext4_put_super
run #13: crashed: KASAN: use-after-free Write in ext4_put_super
run #14: crashed: KASAN: use-after-free Write in ext4_put_super
run #15: crashed: KASAN: use-after-free Write in ext4_put_super
run #16: crashed: INFO: task hung in ext4_put_super
run #17: crashed: INFO: task hung in ext4_put_super
run #18: OK
run #19: OK
testing release v5.11
testing commit f40ddce88593482919761f74910f42f4b84c004b with gcc (GCC) 10.2.1 20210217
kernel signature: 293e6579f0d65cbda46b2d20e15f30555f6e4ea292502f9356c74a1affb84b2f
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: KASAN: use-after-free Write in ext4_put_super
run #2: crashed: KASAN: use-after-free Write in ext4_put_super
run #3: crashed: INFO: task hung in ext4_put_super
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
reproducer seems to be flaky
testing release v5.10
testing commit 2c85ebc57b3e1817b6ce1a6b703928e113a90442 with gcc (GCC) 10.2.1 20210217
kernel signature: aa5dbcb7b6350e128566df7b79649d445731318f591bef7c95206222f351bb67
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: KASAN: use-after-free Write in ext4_put_super
run #2: crashed: KASAN: use-after-free Write in ext4_put_super
run #3: crashed: KASAN: use-after-free Write in ext4_put_super
run #4: crashed: KASAN: use-after-free Write in ext4_put_super
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
testing release v5.9
testing commit bbf5c979011a099af5dc76498918ed7df445635b with gcc (GCC) 10.2.1 20210217
kernel signature: 5c24f3f4b62492843caa7e7e852285d332e09df8819536e003a2c6149fac4abc
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: INFO: task hung in ext4_put_super
run #2: crashed: KASAN: use-after-free Write in ext4_put_super
run #3: crashed: KASAN: use-after-free Write in ext4_put_super
run #4: crashed: KASAN: use-after-free Write in ext4_put_super
run #5: crashed: KASAN: use-after-free Write in ext4_put_super
run #6: crashed: KASAN: use-after-free Write in ext4_put_super
run #7: crashed: KASAN: use-after-free Write in ext4_put_super
run #8: crashed: KASAN: use-after-free Write in ext4_put_super
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
testing release v5.8
testing commit bcf876870b95592b52519ed4aafcf9d95999bc9c with gcc (GCC) 8.4.1 20210217
kernel signature: e064f1b90e3cfa434cb136ae367ce886a75f83b37d3f635477c7b19461094f39
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: KASAN: use-after-free Write in ext4_put_super
run #2: crashed: KASAN: use-after-free Write in ext4_put_super
run #3: crashed: KASAN: use-after-free Write in ext4_put_super
run #4: crashed: KASAN: use-after-free Write in ext4_put_super
run #5: crashed: KASAN: use-after-free Write in ext4_put_super
run #6: crashed: KASAN: use-after-free Write in ext4_put_super
run #7: crashed: KASAN: use-after-free Write in ext4_put_super
run #8: crashed: KASAN: use-after-free Write in ext4_put_super
run #9: crashed: KASAN: use-after-free Write in ext4_put_super
run #10: crashed: KASAN: use-after-free Write in ext4_put_super
run #11: crashed: KASAN: use-after-free Write in ext4_put_super
run #12: crashed: KASAN: use-after-free Write in ext4_put_super
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
testing release v5.7
testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 with gcc (GCC) 8.4.1 20210217
kernel signature: 0c3b42a2623ff57e7e764989f96f47d87aded95e87d9e48275f1a3c8bd52969b
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: KASAN: use-after-free Write in ext4_put_super
run #2: crashed: KASAN: use-after-free Write in ext4_put_super
run #3: crashed: KASAN: use-after-free Write in ext4_put_super
run #4: crashed: KASAN: use-after-free Write in ext4_put_super
run #5: crashed: KASAN: use-after-free Write in ext4_put_super
run #6: crashed: KASAN: use-after-free Write in ext4_put_super
run #7: crashed: KASAN: use-after-free Write in ext4_put_super
run #8: OK
run #9: crashed: KASAN: use-after-free Write in ext4_put_super
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
testing release v5.6
testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.4.1 20210217
kernel signature: d9f64012349e0d74c7c908ab911c6276e4b0f83458da87d57127cd8708aa9c37
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: KASAN: use-after-free Write in ext4_put_super
run #2: crashed: KASAN: use-after-free Write in ext4_put_super
run #3: crashed: KASAN: use-after-free Write in ext4_put_super
run #4: crashed: KASAN: use-after-free Write in ext4_put_super
run #5: crashed: KASAN: use-after-free Write in ext4_put_super
run #6: boot failed: can't ssh into the instance
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
testing release v5.5
testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.4.1 20210217
kernel signature: ba676d29733da0c4728588193fbc641be89b273270ae57d0f4d0c16812a703ca
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: KASAN: use-after-free Write in ext4_put_super
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: crashed: KASAN: use-after-free Write in ext4_put_super
run #10: OK
run #11: OK
run #12: OK
run #13: OK
run #14: OK
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
testing release v5.4
testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.4.1 20210217
kernel signature: 949001b74ebcba9a4ee8693b8e891d0971c58010c6cfc40dc44eae5156602299
run #0: crashed: KASAN: use-after-free Read in ext4_put_super
run #1: crashed: KASAN: use-after-free Read in ext4_put_super
run #2: crashed: KASAN: use-after-free Read in ext4_put_super
run #3: crashed: KASAN: use-after-free Read in ext4_put_super
run #4: crashed: KASAN: use-after-free Read in ext4_put_super
run #5: crashed: KASAN: use-after-free Read in ext4_put_super
run #6: crashed: KASAN: use-after-free Read in ext4_put_super
run #7: OK
run #8: OK
run #9: OK
run #10: OK
run #11: OK
run #12: OK
run #13: crashed: KASAN: use-after-free Read in ext4_put_super
run #14: crashed: KASAN: use-after-free Read in ext4_put_super
run #15: OK
run #16: OK
run #17: OK
run #18: OK
run #19: OK
testing release v5.3
testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.4.1 20210217
kernel signature: 27db41da572d7dda09afa86fde3174208da7993bb7e612668a1cfabfaa835453
all runs: crashed: KASAN: use-after-free Read in ext4_put_super
testing release v5.2
testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.4.1 20210217
kernel signature: fb55f61533c1f812a87ea4d303fbacd0bee896a9e9b47b9c03fd35c7e1df8fcb
run #0: crashed: KASAN: use-after-free Read in ext4_put_super
run #1: crashed: KASAN: use-after-free Read in ext4_put_super
run #2: crashed: KASAN: use-after-free Read in ext4_put_super
run #3: crashed: KASAN: use-after-free Read in ext4_put_super
run #4: crashed: KASAN: use-after-free Read in ext4_put_super
run #5: crashed: KASAN: use-after-free Read in ext4_put_super
run #6: crashed: KASAN: use-after-free Read in ext4_put_super
run #7: crashed: KASAN: use-after-free Read in ext4_put_super
run #8: crashed: KASAN: use-after-free Read in ext4_put_super
run #9: crashed: KASAN: use-after-free Read in ext4_put_super
run #10: crashed: KASAN: use-after-free Read in ext4_put_super
run #11: crashed: KASAN: use-after-free Read in ext4_put_super
run #12: crashed: KASAN: use-after-free Read in ext4_put_super
run #13: crashed: KASAN: use-after-free Read in ext4_put_super
run #14: crashed: KASAN: use-after-free Read in ext4_put_super
run #15: crashed: KASAN: use-after-free Read in ext4_put_super
run #16: crashed: KASAN: use-after-free Read in ext4_put_super
run #17: crashed: KASAN: use-after-free Read in ext4_put_super
run #18: crashed: BUG: MAX_STACK_TRACE_ENTRIES too low!
run #19: crashed: BUG: MAX_STACK_TRACE_ENTRIES too low!
testing release v5.1
testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.4.1 20210217
kernel signature: 7ff787ec748fd4b4054fc566ed6baf33d0070560a739f8fe7451fac0d442fcdd
run #0: crashed: KASAN: use-after-free Read in ext4_put_super
run #1: crashed: KASAN: use-after-free Read in ext4_put_super
run #2: crashed: KASAN: use-after-free Read in ext4_put_super
run #3: crashed: KASAN: use-after-free Read in ext4_put_super
run #4: crashed: KASAN: use-after-free Read in ext4_put_super
run #5: crashed: KASAN: use-after-free Read in ext4_put_super
run #6: crashed: KASAN: use-after-free Read in ext4_put_super
run #7: crashed: KASAN: use-after-free Read in ext4_put_super
run #8: crashed: KASAN: use-after-free Read in ext4_put_super
run #9: crashed: KASAN: use-after-free Read in ext4_put_super
run #10: crashed: KASAN: use-after-free Read in ext4_put_super
run #11: crashed: KASAN: use-after-free Read in ext4_put_super
run #12: crashed: KASAN: use-after-free Read in ext4_put_super
run #13: crashed: KASAN: use-after-free Read in ext4_put_super
run #14: crashed: KASAN: use-after-free Read in ext4_put_super
run #15: crashed: KASAN: use-after-free Read in ext4_put_super
run #16: crashed: BUG: MAX_STACK_TRACE_ENTRIES too low!
run #17: crashed: BUG: MAX_STACK_TRACE_ENTRIES too low!
run #18: crashed: BUG: MAX_STACK_TRACE_ENTRIES too low!
run #19: crashed: BUG: MAX_STACK_TRACE_ENTRIES too low!
testing release v5.0
testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.4.1 20210217
kernel signature: 81b3bf7f25380ba4392ce949e5929e3211138c41f890748c7daf296e91692a03
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: KASAN: use-after-free Write in ext4_put_super
run #2: crashed: KASAN: use-after-free Write in ext4_put_super
run #3: crashed: KASAN: use-after-free Write in ext4_put_super
run #4: crashed: KASAN: use-after-free Write in ext4_put_super
run #5: crashed: KASAN: use-after-free Write in ext4_put_super
run #6: crashed: KASAN: use-after-free Write in ext4_put_super
run #7: crashed: KASAN: use-after-free Write in ext4_put_super
run #8: crashed: KASAN: use-after-free Write in ext4_put_super
run #9: crashed: KASAN: use-after-free Write in ext4_put_super
run #10: crashed: KASAN: use-after-free Write in ext4_put_super
run #11: crashed: KASAN: use-after-free Write in ext4_put_super
run #12: crashed: KASAN: use-after-free Write in ext4_put_super
run #13: crashed: KASAN: use-after-free Write in ext4_put_super
run #14: crashed: KASAN: use-after-free Write in ext4_put_super
run #15: crashed: KASAN: use-after-free Write in ext4_put_super
run #16: crashed: KASAN: use-after-free Write in ext4_put_super
run #17: crashed: KASAN: use-after-free Write in ext4_put_super
run #18: OK
run #19: OK
testing release v4.20
testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.4.1 20210217
kernel signature: fae00066ff3df761fff25e757f4fde5472f3ef97ff43c709aa9903e3977fbe93
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: KASAN: use-after-free Write in ext4_put_super
run #2: crashed: KASAN: use-after-free Write in ext4_put_super
run #3: crashed: KASAN: use-after-free Write in ext4_put_super
run #4: crashed: KASAN: use-after-free Write in ext4_put_super
run #5: crashed: KASAN: use-after-free Write in ext4_put_super
run #6: crashed: KASAN: use-after-free Write in ext4_put_super
run #7: crashed: KASAN: use-after-free Write in ext4_put_super
run #8: crashed: KASAN: use-after-free Write in ext4_put_super
run #9: crashed: KASAN: use-after-free Write in ext4_put_super
run #10: crashed: KASAN: use-after-free Write in ext4_put_super
run #11: crashed: KASAN: use-after-free Write in ext4_put_super
run #12: crashed: KASAN: use-after-free Write in ext4_put_super
run #13: crashed: KASAN: use-after-free Write in ext4_put_super
run #14: crashed: KASAN: use-after-free Write in ext4_put_super
run #15: crashed: KASAN: use-after-free Write in ext4_put_super
run #16: crashed: INFO: task hung in ext4_put_super
run #17: crashed: KASAN: use-after-free Write in ext4_put_super
run #18: OK
run #19: OK
testing release v4.19
testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.4.1 20210217
kernel signature: a1af9f1e793d8b0103c5a9d3bde2af2d2f2a4127a2b8eaf92682ae2173fa9f27
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: KASAN: use-after-free Write in ext4_put_super
run #2: crashed: KASAN: use-after-free Write in ext4_put_super
run #3: crashed: KASAN: use-after-free Write in ext4_put_super
run #4: crashed: KASAN: use-after-free Write in ext4_put_super
run #5: crashed: KASAN: use-after-free Write in ext4_put_super
run #6: crashed: KASAN: use-after-free Write in ext4_put_super
run #7: crashed: KASAN: use-after-free Write in ext4_put_super
run #8: crashed: KASAN: use-after-free Write in ext4_put_super
run #9: crashed: KASAN: use-after-free Write in ext4_put_super
run #10: crashed: KASAN: use-after-free Write in ext4_put_super
run #11: crashed: KASAN: use-after-free Write in ext4_put_super
run #12: crashed: KASAN: use-after-free Write in ext4_put_super
run #13: crashed: KASAN: use-after-free Write in ext4_put_super
run #14: crashed: KASAN: use-after-free Write in ext4_put_super
run #15: crashed: KASAN: use-after-free Write in ext4_put_super
run #16: crashed: INFO: task hung in ext4_put_super
run #17: crashed: KASAN: use-after-free Write in ext4_put_super
run #18: crashed: KASAN: use-after-free Write in ext4_put_super
run #19: crashed: KASAN: use-after-free Write in ext4_put_super
testing release v4.18
testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.4.1 20210217
kernel signature: 9a97fb80dd63159baaa0f79c9e6f7d076a74855f338469606c16ac3aef04b2e0
run #0: crashed: KASAN: use-after-free Write in ext4_put_super
run #1: crashed: KASAN: use-after-free Write in ext4_put_super
run #2: crashed: KASAN: use-after-free Write in ext4_put_super
run #3: crashed: KASAN: use-after-free Write in ext4_put_super
run #4: crashed: KASAN: use-after-free Write in ext4_put_super
run #5: crashed: KASAN: use-after-free Write in ext4_put_super
run #6: crashed: KASAN: use-after-free Write in ext4_put_super
run #7: crashed: KASAN: use-after-free Write in ext4_put_super
run #8: crashed: KASAN: use-after-free Write in ext4_put_super
run #9: crashed: KASAN: use-after-free Write in ext4_put_super
run #10: crashed: KASAN: use-after-free Write in ext4_put_super
run #11: crashed: KASAN: use-after-free Write in ext4_put_super
run #12: crashed: KASAN: use-after-free Write in ext4_put_super
run #13: crashed: INFO: task hung in ext4_put_super
run #14: crashed: KASAN: use-after-free Write in ext4_put_super
run #15: crashed: KASAN: use-after-free Write in ext4_put_super
run #16: crashed: KASAN: use-after-free Write in ext4_put_super
run #17: crashed: KASAN: use-after-free Write in ext4_put_super
run #18: crashed: KASAN: use-after-free Write in ext4_put_super
run #19: crashed: KASAN: use-after-free Write in ext4_put_super
testing release v4.17
testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.4.1 20210217
failed to run ["make" "-j" "64" "ARCH=x86_64" "CC=/syzkaller/shared/bisect_bin/gcc-8.1.0/bin/gcc" "bzImage"]: exit status 2
testing release v4.16
testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.4.1 20210217
orc_dump.c:106:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
orc_dump.c:111:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
elf.c:135:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:140:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.15
testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.4.1 20210217
orc_dump.c:106:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
orc_dump.c:111:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:36:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
elf.c:135:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:140:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.14
testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.4.1 20210217
orc_dump.c:105:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
orc_dump.c:110:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:36:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
elf.c:134:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:139:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.13
testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.4.1 20210217
pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
elf.c:144:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:149:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.12
testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.4.1 20210217
pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
elf.c:141:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:146:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.11
testing commit a351e9b9fc24e982ec2f0e76379a49826036da12 with gcc (GCC) 7.5.0
elf.c:141:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:146:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
testing release v4.10
testing commit c470abd4fde40ea6a0846a2beab642a578c0b8cd with gcc (GCC) 5.5.0
tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes]
elf.c:129:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:134:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
testing release v4.9
testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0
tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes]
elf.c:129:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:134:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
testing release v4.8
testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0
tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes]
elf.c:129:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:134:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
pager.c:33:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
testing release v4.7
testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0
tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes]
pager.c:33:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
elf.c:122:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations]
elf.c:127:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations]
testing release v4.6
testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0
tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes]
pager.c:33:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict]
Reproducer flagged being flaky
revisions tested: 16, total time: 4h44m58.760755086s (build: 1h41m34.32311964s, test: 2h58m13.642157204s)
the crash already happened on the oldest tested release
commit msg: Linux 4.18
crash: KASAN: use-after-free Write in ext4_put_super
EXT4-fs (loop4): re-mounted. Opts: (null)
EXT4-fs (loop1): re-mounted. Opts: (null)
EXT4-fs (loop1): re-mounted. Opts: (null)
EXT4-fs (loop0): re-mounted. Opts: (null)
==================================================================
BUG: KASAN: use-after-free in atomic_inc include/asm-generic/atomic-instrumented.h:102 [inline]
BUG: KASAN: use-after-free in kthread_stop+0x44/0x550 kernel/kthread.c:543
Write of size 4 at addr ffff8800adb0e320 by task syz-executor208/18256

CPU: 1 PID: 18256 Comm: syz-executor208 Not tainted 4.18.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x15a/0x20d lib/dump_stack.c:113
 print_address_description.cold.6+0x9/0x244 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold.7+0x242/0x305 mm/kasan/report.c:396
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13c/0x1b0 mm/kasan/kasan.c:267
EXT4-fs (loop3): re-mounted. Opts: (null)
 kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278
 atomic_inc include/asm-generic/atomic-instrumented.h:102 [inline]
 kthread_stop+0x44/0x550 kernel/kthread.c:543
 ext4_put_super+0x6a9/0xb90 fs/ext4/super.c:981
 generic_shutdown_super+0x12d/0x330 fs/super.c:453
 kill_block_super+0x96/0xe0 fs/super.c:1201
 deactivate_locked_super+0x77/0xd0 fs/super.c:326
 deactivate_super fs/super.c:357 [inline]
 deactivate_super+0x8a/0xa0 fs/super.c:353
 cleanup_mnt+0x9f/0x130 fs/namespace.c:1183
 __cleanup_mnt+0xd/0x10 fs/namespace.c:1190
 task_work_run+0x111/0x180 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:192 [inline]
 exit_to_usermode_loop+0x180/0x1e0 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x47a/0x540 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x44bf67
Code: ff d0 48 89 c7 b8 3c 00 00 00 0f 05 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 a6 00 00 00 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:00007ffcb6c198a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000074d11 RCX: 000000000044bf67
RDX: 00007ffcb6c1996b RSI: 0000000000000002 RDI: 00007ffcb6c19960
RBP: 00007ffcb6c19960 R08: 00000000ffffffff R09: 00007ffcb6c19740
R10: 0000000000708663 R11: 0000000000000202 R12: 00007ffcb6c1aa20
R13: 00000000007085f0 R14: 00007ffcb6c198d0 R15: 00007ffcb6c1aa40

Allocated by task 2:
 save_stack mm/kasan/kasan.c:448 [inline]
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:553
 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:538
 kasan_slab_alloc+0x11/0x20 mm/kasan/kasan.c:490
 slab_post_alloc_hook mm/slab.h:444 [inline]
 slab_alloc_node mm/slub.c:2708 [inline]
 kmem_cache_alloc_node+0xfa/0x380 mm/slub.c:2744
 alloc_task_struct_node kernel/fork.c:157 [inline]
 dup_task_struct kernel/fork.c:802 [inline]
 copy_process.part.5+0x1313/0x6b70 kernel/fork.c:1664
 copy_process kernel/fork.c:1639 [inline]
 _do_fork+0x159/0xb70 kernel/fork.c:2122
 kernel_thread+0x24/0x30 kernel/fork.c:2181
 create_kthread kernel/kthread.c:269 [inline]
 kthreadd+0x4d7/0x730 kernel/kthread.c:585
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:412

Freed by task 9:
 save_stack mm/kasan/kasan.c:448 [inline]
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x167/0x240 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 slab_free_hook mm/slub.c:1373 [inline]
 slab_free_freelist_hook mm/slub.c:1400 [inline]
 slab_free mm/slub.c:2955 [inline]
 kmem_cache_free+0xdd/0x370 mm/slub.c:2971
 free_task_struct kernel/fork.c:162 [inline]
 free_task+0xa5/0xd0 kernel/fork.c:415
 __put_task_struct+0x247/0x2e0 kernel/fork.c:689
 put_task_struct include/linux/sched/task.h:96 [inline]
 delayed_put_task_struct+0x1b4/0x260 kernel/exit.c:180
 __rcu_reclaim kernel/rcu/rcu.h:178 [inline]
 rcu_do_batch kernel/rcu/tree.c:2558 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2818 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2785 [inline]
 rcu_process_callbacks+0x86c/0x1350 kernel/rcu/tree.c:2802
 __do_softirq+0x25c/0x986 kernel/softirq.c:292

The buggy address belongs to the object at ffff8800adb0e300
 which belongs to the cache task_struct of size 6080
The buggy address is located 32 bytes inside of
 6080-byte region [ffff8800adb0e300, ffff8800adb0fac0)
The buggy address belongs to the page:
page:ffffea0002b6c200 count:1 mapcount:0 mapping:ffff8800b602bc00 index:0x0 compound_mapcount: 0
EXT4-fs warning (device loop2): ext4_multi_mount_protect:386: Unable to create kmmpd thread for loop2.
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 0000000000000000 0000000100000001 ffff8800b602bc00
raw: 0000000000000000 0000000000050005 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8800adb0e200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8800adb0e280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8800adb0e300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff8800adb0e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8800adb0e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
EXT4-fs (loop0): re-mounted. Opts: (null)