bisecting fixing commit since 9c0c4d24ac000e52d55348961d3a3ba42065e0cf building syzkaller on 282f03fbbd76ae15c1ed5e934873fbbc47735176 testing commit 9c0c4d24ac000e52d55348961d3a3ba42065e0cf compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 00453a6dc3f46581e848d1cdec7a53df6fdb2cd531d89eafe635281cd7e7e940 all runs: crashed: WARNING: refcount bug in sys_memfd_secret testing current HEAD 5d9f4cf36721aba199975a9be7863a3ff5cd4b59 testing commit 5d9f4cf36721aba199975a9be7863a3ff5cd4b59 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 4165445cc8fbb2f830cc52a7a36c664925b5f9179d15245d08ba339674a4e5e8 all runs: OK # git bisect start 5d9f4cf36721aba199975a9be7863a3ff5cd4b59 9c0c4d24ac000e52d55348961d3a3ba42065e0cf Bisecting: 6979 revisions left to test after this (roughly 13 steps) [624ad333d49e136c54a342ce0009a05b439616be] Merge tag 'docs-5.16' of git://git.lwn.net/linux testing commit 624ad333d49e136c54a342ce0009a05b439616be compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 5725387cfab701274b56ce5106a9b8664ea0a72cb6627ef533ad346ad960a1b0 all runs: OK # git bisect bad 624ad333d49e136c54a342ce0009a05b439616be Bisecting: 4368 revisions left to test after this (roughly 12 steps) [84882cf72cd774cf16fd338bdbf00f69ac9f9194] Revert "net: avoid double accounting for pure zerocopy skbs" testing commit 84882cf72cd774cf16fd338bdbf00f69ac9f9194 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: a8be9d214aed7ac45102541d866ec18a92cacbd3c1c9f7d86842d78029fea2fa all runs: OK # git bisect bad 84882cf72cd774cf16fd338bdbf00f69ac9f9194 Bisecting: 1257 revisions left to test after this (roughly 10 steps) [3d9c64ca52d5a94a49df900e53ff1e60895720dd] ethernet: tehuti: use eth_hw_addr_set() testing commit 3d9c64ca52d5a94a49df900e53ff1e60895720dd compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 0fa633223f91b27850a43fd21f709f27606310b7bb1baf04f85bbd4781cf70cd all runs: crashed: WARNING: refcount bug in sys_memfd_secret # git bisect good 3d9c64ca52d5a94a49df900e53ff1e60895720dd Bisecting: 636 revisions left to test after this (roughly 9 steps) [2619f904b25cd056fba9b4694c57647d6782b1af] Merge tag 'iwlwifi-next-for-kalle-2021-10-28' of git://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/iwlwifi-next testing commit 2619f904b25cd056fba9b4694c57647d6782b1af compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 60ce284848923269e69c6eaa4faa6666074563d3cf0be5fb7b7089c3df7a90be all runs: crashed: WARNING in nsim_dev_reload_destroy # git bisect good 2619f904b25cd056fba9b4694c57647d6782b1af Bisecting: 318 revisions left to test after this (roughly 8 steps) [6689d716fded86e5b85309537e2c42945763eeea] Merge branch 'MCTP-flow-support' testing commit 6689d716fded86e5b85309537e2c42945763eeea compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: df422ad05ed578a4afbcf68b3ab874b5475b53cc9b6e3388a0b2e0a519251107 all runs: OK # git bisect bad 6689d716fded86e5b85309537e2c42945763eeea Bisecting: 138 revisions left to test after this (roughly 7 steps) [411a44c24a561e449b592ff631b7ae321f1eb559] Merge tag 'net-5.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net testing commit 411a44c24a561e449b592ff631b7ae321f1eb559 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: f9c09513d495ac1fcf7ea8666e67f21b86acbe780a490484c24ebb4df1fe39a9 all runs: OK # git bisect bad 411a44c24a561e449b592ff631b7ae321f1eb559 Bisecting: 89 revisions left to test after this (roughly 7 steps) [fc18cc89b9802dbe710cbfb52d0b11b3197ead18] Merge tag 'trace-v5.15-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace testing commit fc18cc89b9802dbe710cbfb52d0b11b3197ead18 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: fd8977d9b4c958bf99bc862ff29100556af4d1eeeb22c56987f279c400eae0d5 all runs: OK # git bisect bad fc18cc89b9802dbe710cbfb52d0b11b3197ead18 Bisecting: 41 revisions left to test after this (roughly 6 steps) [c2b43854aad9e52b422e6c6342a1da2261f98fa5] Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm testing commit c2b43854aad9e52b422e6c6342a1da2261f98fa5 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: b0ac23e8c74947885b35491d83286c9f81efb916c7e5a36e7ac56a205e3f22c0 all runs: OK # git bisect bad c2b43854aad9e52b422e6c6342a1da2261f98fa5 Bisecting: 22 revisions left to test after this (roughly 5 steps) [16bc177666c037b4aa3e1f68f4eac685006c622b] Merge tag 'x86_urgent_for_v5.15_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip testing commit 16bc177666c037b4aa3e1f68f4eac685006c622b compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: b43313dd66618251a64cc7cc65be773189c8b6f6377c3b263f697a0274aef18a all runs: crashed: WARNING: refcount bug in sys_memfd_secret # git bisect good 16bc177666c037b4aa3e1f68f4eac685006c622b Bisecting: 11 revisions left to test after this (roughly 4 steps) [a51aec4109300d843bf144579109d5288856f72a] Merge tag 'pinctrl-v5.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl testing commit a51aec4109300d843bf144579109d5288856f72a compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: b0ac23e8c74947885b35491d83286c9f81efb916c7e5a36e7ac56a205e3f22c0 all runs: OK # git bisect bad a51aec4109300d843bf144579109d5288856f72a Bisecting: 5 revisions left to test after this (roughly 3 steps) [4e5a04be88fe335ad5331f4f8c17f4ebd357e065] pinctrl: amd: disable and mask interrupts on probe testing commit 4e5a04be88fe335ad5331f4f8c17f4ebd357e065 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: cf94cbdca6069d91ccd51b4e3a584fed07e0db77e408476564fa307dd944fe49 all runs: crashed: WARNING: refcount bug in sys_memfd_secret # git bisect good 4e5a04be88fe335ad5331f4f8c17f4ebd357e065 Bisecting: 3 revisions left to test after this (roughly 2 steps) [6c62666d8879238578b727f8e0a821e90c88f87e] Merge tag 'sched_urgent_for_v5.15_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip testing commit 6c62666d8879238578b727f8e0a821e90c88f87e compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: d473ac4de737d138e716042db2e5862e0ad62e4182c7e71ea8f9689f14319d32 all runs: crashed: WARNING: refcount bug in sys_memfd_secret # git bisect good 6c62666d8879238578b727f8e0a821e90c88f87e Bisecting: 1 revision left to test after this (roughly 1 step) [b20078fd69a3da08d85c79b95101cf25c4afcc97] Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs testing commit b20078fd69a3da08d85c79b95101cf25c4afcc97 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 7c3c4c961fddaaa5c4658aec6a1d66f803e21ffbab659491710e158fb1d01f06 all runs: crashed: WARNING: refcount bug in sys_memfd_secret # git bisect good b20078fd69a3da08d85c79b95101cf25c4afcc97 Bisecting: 0 revisions left to test after this (roughly 0 steps) [87066fdd2e30fe9dd531125d95257c118a74617e] Revert "mm/secretmem: use refcount_t instead of atomic_t" testing commit 87066fdd2e30fe9dd531125d95257c118a74617e compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: b0ac23e8c74947885b35491d83286c9f81efb916c7e5a36e7ac56a205e3f22c0 all runs: OK # git bisect bad 87066fdd2e30fe9dd531125d95257c118a74617e 87066fdd2e30fe9dd531125d95257c118a74617e is the first bad commit commit 87066fdd2e30fe9dd531125d95257c118a74617e Author: Linus Torvalds Date: Sun Oct 24 09:48:33 2021 -1000 Revert "mm/secretmem: use refcount_t instead of atomic_t" This reverts commit 110860541f443f950c1274f217a1a3e298670a33. Converting the "secretmem_users" counter to a refcount is incorrect, because a refcount is special in zero and can't just be incremented (but a count of users is not, and "no users" is actually perfectly valid and not a sign of a free'd resource). Reported-by: syzbot+75639e6a0331cd61d3e2@syzkaller.appspotmail.com Cc: Jordy Zomer Cc: Kees Cook , Cc: Jordy Zomer Cc: James Bottomley Cc: Mike Rapoport Cc: Andrew Morton Signed-off-by: Linus Torvalds mm/secretmem.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) culprit signature: b0ac23e8c74947885b35491d83286c9f81efb916c7e5a36e7ac56a205e3f22c0 parent signature: 7c3c4c961fddaaa5c4658aec6a1d66f803e21ffbab659491710e158fb1d01f06 revisions tested: 16, total time: 3h33m20.403351251s (build: 1h45m23.466348303s, test: 1h46m16.940869233s) first good commit: 87066fdd2e30fe9dd531125d95257c118a74617e Revert "mm/secretmem: use refcount_t instead of atomic_t" recipients (to): ["akpm@linux-foundation.org" "linux-mm@kvack.org" "torvalds@linux-foundation.org"] recipients (cc): ["linux-kernel@vger.kernel.org"]