Hi, First of all, sorry for the incorrect reply as I was not subscribed to the mailing list. A colleague and I have tested Miklos patch[1] on top of Fedora 31 5.5.7 kernel and it fixes a kernel oops[2] when using rootless containers in Podman. Fix has been running for a few days now, and the issue was normally reproducible within a few minutes. Tested-by: Bruno Thomsen <bruno.thomsen@xxxxxxxxx> /Bruno [1] https://lore.kernel.org/linux-fsdevel/CAJfpegvBguKcNZk-p7sAtSuNH_7HfdCyYvo8Wh7X6P=hT=kPrA@xxxxxxxxxxxxxx/ [2] Oops when running podman workload. kernel: BUG: kernel NULL pointer dereference, address: 0000000000000001 kernel: #PF: supervisor instruction fetch in kernel mode kernel: #PF: error_code(0x0010) - not-present page kernel: PGD 8000000e4cd85067 P4D 8000000e4cd85067 PUD e4cd80067 PMD 0 kernel: Oops: 0010 [#1] SMP PTI kernel: CPU: 27 PID: 3422 Comm: fuse-overlayfs Not tainted 5.5.5-200.fc31.x86_64 #1 kernel: Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 kernel: RIP: 0010:0x1 kernel: Code: Bad RIP value. kernel: RSP: 0018:ffffaa0d4196fc30 EFLAGS: 00010202 kernel: RAX: 0000000000000001 RBX: ffff8b5f344c2250 RCX: 0000000000000000 kernel: RDX: 0000000000000000 RSI: ffffaa0d4932fbb8 RDI: ffff8b65ac586800 kernel: RBP: ffff8b5f344c2240 R08: ffff8b5f344c22a0 R09: ffffaa0d4196fbd0 kernel: R10: ffff8b65a5c71888 R11: 0000000000000001 R12: ffff8b65ac586800 kernel: R13: 0000000000000001 R14: ffff8b65ab535dc0 R15: ffff8b5f344c2240 kernel: FS: 00007fb4239a7b80(0000) GS:ffff8b65b98c0000(0000) knlGS:0000000000000000 kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kernel: CR2: ffffffffffffffd7 CR3: 0000000e4cd38004 CR4: 0000000000360ee0 kernel: DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 kernel: DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 kernel: Call Trace: kernel: ? fuse_request_end+0xbc/0x1f0 [fuse] kernel: ? fuse_dev_do_write+0x25e/0xe70 [fuse] kernel: ? lookup_fast+0xca/0x280 kernel: ? fuse_dev_write+0x53/0x90 [fuse] kernel: ? do_iter_readv_writev+0x158/0x1d0 kernel: ? do_iter_write+0x7d/0x190 kernel: ? vfs_writev+0xa6/0xf0 kernel: ? _copy_to_user+0x28/0x30 kernel: ? readlink_copy+0x5a/0x80 kernel: ? do_writev+0x6b/0x110 kernel: ? do_syscall_64+0x5b/0x1c0 kernel: ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 kernel: Modules linked in: tun ip6t_REJECT nf_reject_ipv6 ip6t_rpfilter ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle ip6table_raw ip6table_> kernel: CR2: 0000000000000001
