bisecting fixing commit since 14cfdbd39e316efd91ae6e403ef8211f0b022603 building syzkaller on 78267cec1aaa5e066d66e6a6c76fea1753e51b46 testing commit 14cfdbd39e316efd91ae6e403ef8211f0b022603 with gcc (GCC) 8.1.0 kernel signature: 83ed550d37e19287b936203efec9b42964ec69d044fdadaef3e6e68495c3f915 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in generic_perform_write testing current HEAD 17a87580a8856170d59aab302226811a4ae69149 testing commit 17a87580a8856170d59aab302226811a4ae69149 with gcc (GCC) 8.1.0 kernel signature: 51d3254ef20e40f9aa3e4d4e85671195dd862d35a6b70a433e99f7ccfc100047 all runs: OK # git bisect start 17a87580a8856170d59aab302226811a4ae69149 14cfdbd39e316efd91ae6e403ef8211f0b022603 Bisecting: 898 revisions left to test after this (roughly 10 steps) [62fe53c2572fd04e56c76a27cfaecadcb4bf12f8] scsi: ibmvscsi: Fix WARN_ON during event pool release testing commit 62fe53c2572fd04e56c76a27cfaecadcb4bf12f8 with gcc (GCC) 8.1.0 kernel signature: f50ebbd3389763ed8b8757d3531fb9508600e7b20d17d0f1266f97620afabda3 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in generic_perform_write # git bisect good 62fe53c2572fd04e56c76a27cfaecadcb4bf12f8 Bisecting: 449 revisions left to test after this (roughly 9 steps) [81130a47b26e70e23b9288c72ba2705ee4ec7554] sparc64: fix misuses of access_process_vm() in genregs32_[sg]et() testing commit 81130a47b26e70e23b9288c72ba2705ee4ec7554 with gcc (GCC) 8.1.0 kernel signature: ecd8171246f57a92ccf6d34d23688dcb61fe673b13748bce7e0af3be4df106fa all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in generic_perform_write # git bisect good 81130a47b26e70e23b9288c72ba2705ee4ec7554 Bisecting: 224 revisions left to test after this (roughly 8 steps) [f04928c3c2627deb43acd6724991d4573a4be7c8] md: add feature flag MD_FEATURE_RAID0_LAYOUT testing commit f04928c3c2627deb43acd6724991d4573a4be7c8 with gcc (GCC) 8.1.0 kernel signature: 8d35a22f6efef83560a50cf1de910e36bd7ecaa27ff41018a4328cae67f207e2 all runs: OK # git bisect bad f04928c3c2627deb43acd6724991d4573a4be7c8 Bisecting: 112 revisions left to test after this (roughly 7 steps) [549ff843327f39584499b25c6caa044507771bbf] USB: host: ehci-mxc: Add error handling in ehci_mxc_drv_probe() testing commit 549ff843327f39584499b25c6caa044507771bbf with gcc (GCC) 8.1.0 kernel signature: 7f57763b880877e92ae46adc35b6763e3da4fadb3f214509b68a15ae317e5791 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in generic_perform_write # git bisect good 549ff843327f39584499b25c6caa044507771bbf Bisecting: 56 revisions left to test after this (roughly 6 steps) [1b72133e8333b7b8b0d3c52bdcbc30bcf35ce4e8] NTB: ntb_test: Fix bug when counting remote files testing commit 1b72133e8333b7b8b0d3c52bdcbc30bcf35ce4e8 with gcc (GCC) 8.1.0 kernel signature: 8b3cdc08e624519c963b463447d9736b4415382ded34e2cb776e2ebf51c683ba all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in generic_perform_write # git bisect good 1b72133e8333b7b8b0d3c52bdcbc30bcf35ce4e8 Bisecting: 28 revisions left to test after this (roughly 5 steps) [051bf267b1fabba8a585a185eb816bf0006bdae6] ext4: fix partial cluster initialization when splitting extent testing commit 051bf267b1fabba8a585a185eb816bf0006bdae6 with gcc (GCC) 8.1.0 kernel signature: 90dda461fb79ab80d50911d5c3ecc85c0241d766e68fb21781553a9c1bff32b2 all runs: crashed: BUG: unable to handle kernel NULL pointer dereference in generic_perform_write # git bisect good 051bf267b1fabba8a585a185eb816bf0006bdae6 Bisecting: 14 revisions left to test after this (roughly 4 steps) [5bf01fce23eafad5dd56dad58fa908ee382f13d9] mtd: rawnand: plat_nand: Fix the probe error path testing commit 5bf01fce23eafad5dd56dad58fa908ee382f13d9 with gcc (GCC) 8.1.0 kernel signature: 49247e429f0358e30089c28068d8e4a29bba6992def68cf02904a60117232c72 all runs: OK # git bisect bad 5bf01fce23eafad5dd56dad58fa908ee382f13d9 Bisecting: 6 revisions left to test after this (roughly 3 steps) [f92c582dd871a565d816988a76b80cc140680feb] mtd: rawnand: diskonchip: Fix the probe error path testing commit f92c582dd871a565d816988a76b80cc140680feb with gcc (GCC) 8.1.0 kernel signature: 1e826c8454b37ea6ccbf5c89c81aa7f5a86317c1605775715ebb617d15bbbd11 all runs: OK # git bisect bad f92c582dd871a565d816988a76b80cc140680feb Bisecting: 3 revisions left to test after this (roughly 2 steps) [4cc4e2dbf958a0bb7a0f3b05c79fc4232d3c2398] x86/boot/compressed: Relax sed symbol type regex for LLVM ld.lld testing commit 4cc4e2dbf958a0bb7a0f3b05c79fc4232d3c2398 with gcc (GCC) 8.1.0 kernel signature: a3d98e715dfca4a0a1bed7d4da276c34e6410253928d5ec85ad21beef7d25951 all runs: OK # git bisect bad 4cc4e2dbf958a0bb7a0f3b05c79fc4232d3c2398 Bisecting: 0 revisions left to test after this (roughly 1 step) [e0a59a6e860f2a6edc465058fd9fb772efcbd9a6] drm/dp_mst: Increase ACT retry timeout to 3s testing commit e0a59a6e860f2a6edc465058fd9fb772efcbd9a6 with gcc (GCC) 8.1.0 kernel signature: 94ecffff3224c97e612c41dd691341315af0562e37f637ad333ab0082c885da9 all runs: OK # git bisect bad e0a59a6e860f2a6edc465058fd9fb772efcbd9a6 Bisecting: 0 revisions left to test after this (roughly 0 steps) [5dbb625573abf67b9f7d6992c8e3f57acaef5946] ext4: avoid race conditions when remounting with options that change dax testing commit 5dbb625573abf67b9f7d6992c8e3f57acaef5946 with gcc (GCC) 8.1.0 kernel signature: ac118c7d5cffa368a9950271cf3acf4b7d81e6a5c65cbdccbe3ee9cedfaa1246 all runs: OK # git bisect bad 5dbb625573abf67b9f7d6992c8e3f57acaef5946 5dbb625573abf67b9f7d6992c8e3f57acaef5946 is the first bad commit commit 5dbb625573abf67b9f7d6992c8e3f57acaef5946 Author: Theodore Ts'o Date: Wed Jun 10 11:16:37 2020 -0400 ext4: avoid race conditions when remounting with options that change dax [ Upstream commit 829b37b8cddb1db75c1b7905505b90e593b15db1 ] Trying to change dax mount options when remounting could allow mount options to be enabled for a small amount of time, and then the mount option change would be reverted. In the case of "mount -o remount,dax", this can cause a race where files would temporarily treated as DAX --- and then not. Cc: stable@kernel.org Reported-by: syzbot+bca9799bf129256190da@syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin fs/ext4/super.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) culprit signature: ac118c7d5cffa368a9950271cf3acf4b7d81e6a5c65cbdccbe3ee9cedfaa1246 parent signature: 90dda461fb79ab80d50911d5c3ecc85c0241d766e68fb21781553a9c1bff32b2 revisions tested: 13, total time: 3h40m23.025158216s (build: 2h1m20.34076216s, test: 1h37m26.439528366s) first good commit: 5dbb625573abf67b9f7d6992c8e3f57acaef5946 ext4: avoid race conditions when remounting with options that change dax cc: ["adilger.kernel@dilger.ca" "linux-ext4@vger.kernel.org" "linux-kernel@vger.kernel.org" "sashal@kernel.org" "tytso@mit.edu"]