Here are some details from proc what is happening on our servers. Both running 4.15.0-47-generic.
server13 / uptime 2 days # cat /proc/fs/cifs/Stats Resources in use CIFS Session: 1 Share (unique mount targets): 2 SMB Request/Response Buffer: 1 Pool size: 5 SMB Small Req/Resp Buffer: 1 Pool size: 30 Operations (MIDs): 0 7 session 14 share reconnects Total vfs operations: 7223031 maximum at one time: 102 1) \\server\share SMBs: 13497286 Negotiates: 0 sent 0 failed SessionSetups: 0 sent 0 failed Logoffs: 0 sent 0 failed TreeConnects: 502 sent 0 failed TreeDisconnects: 0 sent 0 failed Creates: 0 sent 466291 failed Closes: 0 sent 2 failed Flushes: 0 sent 0 failed Reads: 0 sent 19 failed Writes: 0 sent 0 failed Locks: 0 sent 0 failed IOCTLs: 0 sent 0 failed Cancels: 0 sent 0 failed Echos: 0 sent 0 failed QueryDirectories: 0 sent 14011 failed ChangeNotifies: 0 sent 0 failed QueryInfos: 0 sent 0 failed SetInfos: 0 sent 0 failed OplockBreaks: 0 sent 16 failed server15 / uptime 5 days # cat /proc/fs/cifs/Stats Resources in use CIFS Session: 1 Share (unique mount targets): 2 SMB Request/Response Buffer: 1 Pool size: 5 SMB Small Req/Resp Buffer: 1 Pool size: 30 Operations (MIDs): 0 1 session 2 share reconnects Total vfs operations: 118861442 maximum at one time: 52 1) \\server\share SMBs: 122017565 Negotiates: 0 sent 0 failed SessionSetups: 0 sent 0 failed Logoffs: 0 sent 0 failed TreeConnects: 19970 sent 0 failed TreeDisconnects: 0 sent 0 failed Creates: 0 sent 738187 failed Closes: 0 sent 0 failed Flushes: 0 sent 0 failed Reads: 0 sent 41 failed Writes: 0 sent 0 failed Locks: 0 sent 0 failed IOCTLs: 0 sent 0 failed Cancels: 0 sent 0 failed Echos: 0 sent 0 failed QueryDirectories: 0 sent 9776 failed ChangeNotifies: 0 sent 0 failed QueryInfos: 0 sent 0 failed SetInfos: 0 sent 0 failed OplockBreaks: 0 sent 3301 failed -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1824981 Title: cifs set_oplock buffer overflow in strcat Status in linux package in Ubuntu: Confirmed Bug description: Ubuntu 18.04.2 LTS Linux SRV013 4.15.0-47-generic #50-Ubuntu SMP Wed Mar 13 10:44:52 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux DELL R740, 2 CPU (40 Cores, 80 Threads), 384 GiB RAM top - 12:39:53 up 3:41, 4 users, load average: 66.19, 64.06, 76.90 Tasks: 1076 total, 1 running, 675 sleeping, 12 stopped, 1 zombie %Cpu(s): 28.2 us, 0.3 sy, 0.0 ni, 71.5 id, 0.0 wa, 0.0 hi, 0.1 si, 0.0 st KiB Mem : 39483801+total, 24077185+free, 57428284 used, 96637872 buff/cache KiB Swap: 999420 total, 999420 free, 0 used. 33477683+avail Mem We've seen the following bug many times since we introduced new machines running Ubuntu 18. Wasn't an issue older machines running Ubuntu 16. Three different machines are affected, so it's rather not a hardware issue. | detected buffer overflow in strcat | ------------[ cut here ]------------ | kernel BUG at /build/linux-6ZmFRN/linux-4.15.0/lib/string.c:1052! | invalid opcode: 0000 [#1] SMP PTI | Modules linked in: [...] | Hardware name: Dell Inc. PowerEdge R740/0923K0, BIOS 1.6.11 11/20/2018 | RIP: 0010:fortify_panic+0x13/0x22 | [...] | Call Trace: | smb21_set_oplock_level+0x147/0x1a0 [cifs] | smb3_set_oplock_level+0x22/0x90 [cifs] | smb2_set_fid+0x76/0xb0 [cifs] | cifs_new_fileinfo+0x259/0x390 [cifs] | ? smb2_get_lease_key+0x40/0x40 [cifs] | ? cifs_new_fileinfo+0x259/0x390 [cifs] | cifs_open+0x3db/0x8d0 [cifs] | [...] (Full dmesg output attached) After hitting this bug there are many cifs related dmesg entries, processes lock up and eventually the systems freezes. The share is mounted using: //server/share /mnt/server/ cifs defaults,auto,iocharset=utf8,noperm,file_mode=0777,dir_mode=0777,credentials=/root/passwords/share,domain=myDomain,uid=myUser,gid=10513,mfsymlinks Currently we're testing the cifs mount options "cache=none" as the bug seems to be oplock related. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1824981/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
