bisecting fixing commit since ddef1e8e3f6eb26034833b7255e3fa584d54a230 building syzkaller on c9610487d8c10f7b4ffb32764a6720cbbdfe6058 testing commit ddef1e8e3f6eb26034833b7255e3fa584d54a230 with gcc (GCC) 8.1.0 kernel signature: 5893b90fd292d9c3a58c7be2ab8f08ebc09a7605 all runs: crashed: WARNING: suspicious RCU usage in shmem_add_seals testing current HEAD bfb9e5c03076a446b1f4f6a523ddc8d723c907a6 testing commit bfb9e5c03076a446b1f4f6a523ddc8d723c907a6 with gcc (GCC) 8.1.0 kernel signature: baaf370a106362c3e0c239e3949f544bfe51253d all runs: OK # git bisect start bfb9e5c03076a446b1f4f6a523ddc8d723c907a6 ddef1e8e3f6eb26034833b7255e3fa584d54a230 Bisecting: 683 revisions left to test after this (roughly 10 steps) [4e846d399cde242861c0705a702d95a0e707d4fc] vhost/vsock: split packets to send using multiple buffers testing commit 4e846d399cde242861c0705a702d95a0e707d4fc with gcc (GCC) 8.1.0 kernel signature: 8620b9428618777e52c1f4808262fff5549ee299 all runs: OK # git bisect bad 4e846d399cde242861c0705a702d95a0e707d4fc Bisecting: 341 revisions left to test after this (roughly 9 steps) [bf95ccce798daaf0a0dbea2927d51894a45b9d7d] iio: adc: max9611: explicitly cast gain_selectors testing commit bf95ccce798daaf0a0dbea2927d51894a45b9d7d with gcc (GCC) 8.1.0 kernel signature: 37a7d77ed90f8d65fb2f2ad818fd3c637c8c6662 all runs: crashed: WARNING: suspicious RCU usage in shmem_add_seals # git bisect good bf95ccce798daaf0a0dbea2927d51894a45b9d7d Bisecting: 170 revisions left to test after this (roughly 8 steps) [d7bb792bc8ff8e96ea344f6752d7749f82e1ff46] vfio/pci: Mask buggy SR-IOV VF INTx support testing commit d7bb792bc8ff8e96ea344f6752d7749f82e1ff46 with gcc (GCC) 8.1.0 kernel signature: 5e6ea238f1cf15a1a0dad6b9bcabd408b974e899 all runs: crashed: WARNING: suspicious RCU usage in shmem_add_seals # git bisect good d7bb792bc8ff8e96ea344f6752d7749f82e1ff46 Bisecting: 85 revisions left to test after this (roughly 7 steps) [191cda60bf0877656e77608650c7294bae2594e4] mtd: rawnand: sh_flctl: Use proper enum for flctl_dma_fifo0_transfer testing commit 191cda60bf0877656e77608650c7294bae2594e4 with gcc (GCC) 8.1.0 kernel signature: 10e5be79e0f73007300efc1bac1bd9ffc85644df all runs: OK # git bisect bad 191cda60bf0877656e77608650c7294bae2594e4 Bisecting: 42 revisions left to test after this (roughly 5 steps) [723aef6434dd82e8b4ded65eabafccab9174c5fc] spi: mediatek: use correct mata->xfer_len when in fifo transfer testing commit 723aef6434dd82e8b4ded65eabafccab9174c5fc with gcc (GCC) 8.1.0 kernel signature: ca3c481d87e390a79b540cab0f4951298c0b7645 all runs: OK # git bisect bad 723aef6434dd82e8b4ded65eabafccab9174c5fc Bisecting: 20 revisions left to test after this (roughly 4 steps) [9c71829435fc21a454786599c5a3a80cf3a3ae8e] scsi: NCR5380: Clear all unissued commands on host reset testing commit 9c71829435fc21a454786599c5a3a80cf3a3ae8e with gcc (GCC) 8.1.0 kernel signature: 3e46d22b4ea5894d9a534510b2f464091c6ddc1c all runs: crashed: WARNING: suspicious RCU usage in shmem_add_seals # git bisect good 9c71829435fc21a454786599c5a3a80cf3a3ae8e Bisecting: 10 revisions left to test after this (roughly 3 steps) [a583b37a088b60668ca5d03484348cbf1f985280] arm64: dts: lg: Fix SPI controller node names testing commit a583b37a088b60668ca5d03484348cbf1f985280 with gcc (GCC) 8.1.0 kernel signature: 6e9a8babb1ad3f4c25a2e80e1af85805f582d914 all runs: crashed: WARNING: suspicious RCU usage in shmem_add_seals # git bisect good a583b37a088b60668ca5d03484348cbf1f985280 Bisecting: 5 revisions left to test after this (roughly 3 steps) [2b149bb378bc34545549d2e8c35f2bbdf1debc92] fuse: use READ_ONCE on congestion_threshold and max_background testing commit 2b149bb378bc34545549d2e8c35f2bbdf1debc92 with gcc (GCC) 8.1.0 kernel signature: 8ee523d91c25a840f5cc881f666d7192d3f2fa90 all runs: crashed: WARNING: suspicious RCU usage in shmem_add_seals # git bisect good 2b149bb378bc34545549d2e8c35f2bbdf1debc92 Bisecting: 2 revisions left to test after this (roughly 2 steps) [988f701a805bf980e70a557894d26564e10fc1a6] memfd: Use radix_tree_deref_slot_protected to avoid the warning. testing commit 988f701a805bf980e70a557894d26564e10fc1a6 with gcc (GCC) 8.1.0 kernel signature: f2ca3fabd6c94a48702edb08960dbd2e9fbb9252 all runs: OK # git bisect bad 988f701a805bf980e70a557894d26564e10fc1a6 Bisecting: 0 revisions left to test after this (roughly 1 step) [7fdedf0c8d8eb93390c94533057d0666a10efd9e] net: phy: mdio-bcm-unimac: mark PM functions as __maybe_unused testing commit 7fdedf0c8d8eb93390c94533057d0666a10efd9e with gcc (GCC) 8.1.0 kernel signature: 13192bcf3cf6bd7453abb33fa4ad89413f8c798c all runs: crashed: WARNING: suspicious RCU usage in shmem_add_seals # git bisect good 7fdedf0c8d8eb93390c94533057d0666a10efd9e 988f701a805bf980e70a557894d26564e10fc1a6 is the first bad commit commit 988f701a805bf980e70a557894d26564e10fc1a6 Author: zhong jiang Date: Mon Nov 18 11:26:07 2019 +0800 memfd: Use radix_tree_deref_slot_protected to avoid the warning. The commit 391d4ee568b5 ("memfd: Fix locking when tagging pins") introduces the following warning messages. *WARNING: suspicious RCU usage in memfd_wait_for_pins* It is because we still use radix_tree_deref_slot without read_rcu_lock. We should use radix_tree_deref_slot_protected instead in the case. Cc: stable@vger.kernel.org Fixes: 391d4ee568b5 ("memfd: Fix locking when tagging pins") Signed-off-by: zhong jiang Reviewed-by: Matthew Wilcox (Oracle) Signed-off-by: Greg Kroah-Hartman mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) culprit signature: f2ca3fabd6c94a48702edb08960dbd2e9fbb9252 parent signature: 13192bcf3cf6bd7453abb33fa4ad89413f8c798c revisions tested: 12, total time: 2h50m28.018020629s (build: 1h37m10.176452698s, test: 1h12m14.509597859s) first good commit: 988f701a805bf980e70a557894d26564e10fc1a6 memfd: Use radix_tree_deref_slot_protected to avoid the warning. cc: ["gregkh@linuxfoundation.org" "willy@infradead.org" "zhongjiang@huawei.com"]