bisecting fixing commit since fbc5fe7a54d02e11972e3b2a5ddb6ffc88162c8f building syzkaller on f879db37f90dcefb681897d2e486c11d8298cb72 testing commit fbc5fe7a54d02e11972e3b2a5ddb6ffc88162c8f with gcc (GCC) 8.1.0 kernel signature: 3fc0fe68b13973b74d4818097434502fb19650f3ba31c74b3480be385cd3ccc2 run #0: crashed: BUG: unable to handle kernel paging request in evdev_open 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 testing current HEAD e0f8b8a65a473a8baa439cf865a694bbeb83fe90 testing commit e0f8b8a65a473a8baa439cf865a694bbeb83fe90 with gcc (GCC) 8.1.0 kernel signature: 13f8816780e0acc4f4916f41916e1b0f54409154295b8a788348936f2b004c4c all runs: OK # git bisect start e0f8b8a65a473a8baa439cf865a694bbeb83fe90 fbc5fe7a54d02e11972e3b2a5ddb6ffc88162c8f Bisecting: 783 revisions left to test after this (roughly 10 steps) [5fac6ee295213de276fb0da852d773af43c24d46] scsi: iscsi: qla4xxx: fix double free in probe testing commit 5fac6ee295213de276fb0da852d773af43c24d46 with gcc (GCC) 8.1.0 kernel signature: 1c645c6b984cedcc330dcd9bdcf4483dac5b5fcea8247b44069bf42c25410214 run #0: crashed: KASAN: use-after-free Read in cdev_put 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 5fac6ee295213de276fb0da852d773af43c24d46 Bisecting: 391 revisions left to test after this (roughly 9 steps) [526eb7a254e9ffabfe567438dc091ad5ebb5c7ee] staging: most: cdev: add missing check for cdev_add failure testing commit 526eb7a254e9ffabfe567438dc091ad5ebb5c7ee with gcc (GCC) 8.1.0 kernel signature: e9e0bc330324fa43c44be198af45dec17f470162d8ceb9cec29d225d74609e31 all runs: OK # git bisect bad 526eb7a254e9ffabfe567438dc091ad5ebb5c7ee Bisecting: 195 revisions left to test after this (roughly 8 steps) [8496401c9de59ad878ce13a05a717c62c41b4795] hsr: reset network header when supervision frame is created testing commit 8496401c9de59ad878ce13a05a717c62c41b4795 with gcc (GCC) 8.1.0 kernel signature: 862bb21937386c389973b7744074fd806a7f07de5fac3b2db2d99b7d371b949e all runs: OK # git bisect bad 8496401c9de59ad878ce13a05a717c62c41b4795 Bisecting: 97 revisions left to test after this (roughly 7 steps) [f1cf84a64527c94c24e009e73bf2c38ce2361596] net: stmmac: RX buffer size must be 16 byte aligned testing commit f1cf84a64527c94c24e009e73bf2c38ce2361596 with gcc (GCC) 8.1.0 kernel signature: 9e584c6192961ed142620004b46cae25cfdd1c781877e7d7a21ad69aca9f3b3b all runs: OK # git bisect bad f1cf84a64527c94c24e009e73bf2c38ce2361596 Bisecting: 48 revisions left to test after this (roughly 6 steps) [2d7c27957cac081eeacea7c38d8c9c59049883dc] media: usb: fix memory leak in af9005_identify_state testing commit 2d7c27957cac081eeacea7c38d8c9c59049883dc with gcc (GCC) 8.1.0 kernel signature: c40027e3081e61921f8a989f2546c34469481fcd719473f22ce280b8f4455309 all runs: OK # git bisect bad 2d7c27957cac081eeacea7c38d8c9c59049883dc Bisecting: 24 revisions left to test after this (roughly 5 steps) [ee4cdf398aeceae9560601dfe5953e93455b0f0d] locks: print unsigned ino in /proc/locks testing commit ee4cdf398aeceae9560601dfe5953e93455b0f0d with gcc (GCC) 8.1.0 kernel signature: 8821037e8bb4b0cb7060915a7721526b63bc9ecdcf9005379f2f8face1c331d3 all runs: OK # git bisect bad ee4cdf398aeceae9560601dfe5953e93455b0f0d Bisecting: 11 revisions left to test after this (roughly 4 steps) [54e15cac21c92a273b1163684670a807885fdd1c] xfs: fix mount failure crash on invalid iclog memory access testing commit 54e15cac21c92a273b1163684670a807885fdd1c with gcc (GCC) 8.1.0 kernel signature: 1fcc468e89f488baeaa2e73ce69bec39e699c00891020c80062d426b8c31c100 all runs: OK # git bisect bad 54e15cac21c92a273b1163684670a807885fdd1c Bisecting: 5 revisions left to test after this (roughly 3 steps) [42c5538af3c01b79f1f06f147172a1a295376b2f] s390/cpum_sf: Adjust sampling interval to avoid hitting sample limits testing commit 42c5538af3c01b79f1f06f147172a1a295376b2f with gcc (GCC) 8.1.0 kernel signature: 69cceb2574c9af312c8378b611929315cd5daa2cf9f5acdcc9095dec3b77e09d run #0: crashed: BUG: unable to handle kernel paging request in evdev_open 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 42c5538af3c01b79f1f06f147172a1a295376b2f Bisecting: 2 revisions left to test after this (roughly 2 steps) [0ce254bc68edf06f93d3c0271851c619ff729d31] xen-blkback: prevent premature module unload testing commit 0ce254bc68edf06f93d3c0271851c619ff729d31 with gcc (GCC) 8.1.0 kernel signature: 7e9d5a254b4032e2ba57e027930648ae3e9d49a43c68088be4e58ed3a4fa6ab3 all runs: OK # git bisect bad 0ce254bc68edf06f93d3c0271851c619ff729d31 Bisecting: 0 revisions left to test after this (roughly 1 step) [556f40b79de5e23fba28f5e35831d1526df52a26] IB/mlx4: Follow mirror sequence of device add during device removal testing commit 556f40b79de5e23fba28f5e35831d1526df52a26 with gcc (GCC) 8.1.0 kernel signature: 9d2e0366744d7a20c14d8fec9990fc6841a9b22bb925ec68c90436c2353e2db3 run #0: crashed: BUG: unable to handle kernel paging request in evdev_open 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 556f40b79de5e23fba28f5e35831d1526df52a26 0ce254bc68edf06f93d3c0271851c619ff729d31 is the first bad commit commit 0ce254bc68edf06f93d3c0271851c619ff729d31 Author: Paul Durrant Date: Tue Dec 10 14:53:05 2019 +0000 xen-blkback: prevent premature module unload [ Upstream commit fa2ac657f9783f0891b2935490afe9a7fd29d3fa ] Objects allocated by xen_blkif_alloc come from the 'blkif_cache' kmem cache. This cache is destoyed when xen-blkif is unloaded so it is necessary to wait for the deferred free routine used for such objects to complete. This necessity was missed in commit 14855954f636 "xen-blkback: allow module to be cleanly unloaded". This patch fixes the problem by taking/releasing extra module references in xen_blkif_alloc/free() respectively. Signed-off-by: Paul Durrant Reviewed-by: Roger Pau Monné Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin drivers/block/xen-blkback/xenbus.c | 10 ++++++++++ 1 file changed, 10 insertions(+) culprit signature: 7e9d5a254b4032e2ba57e027930648ae3e9d49a43c68088be4e58ed3a4fa6ab3 parent signature: 9d2e0366744d7a20c14d8fec9990fc6841a9b22bb925ec68c90436c2353e2db3 revisions tested: 12, total time: 3h56m47.891306765s (build: 1h42m29.550267934s, test: 2h13m10.929095468s) first good commit: 0ce254bc68edf06f93d3c0271851c619ff729d31 xen-blkback: prevent premature module unload cc: ["jgross@suse.com" "pdurrant@amazon.com" "roger.pau@citrix.com" "sashal@kernel.org"]