Does anyone know why boinc-client has started to try and read b11:0? Selinux is not keen on allowing it.

type=AVC msg=audit(1505173244.881:301): avc: denied { read } for pid=2883 comm="boinc_client" name="b11:0" dev="tmpfs" ino=17553 scontext=system_u:system_r:boinc_t:s0 tcontext=system_u:object_r:udev_var_run_t:s0 tclass=file permissive=0

Could you tell where exactly that file is and its type (regular or some special file)?

I think I found it in /run/udev/data/b11:0 and it looks like udev config info for the dvd (the Sekinux context is the same). Any idea why boinc-client wants this access?

S:cdrom
S:disk/by-path/pci-0000:00:1f.2-ata-2
S:disk/by-id/ata-ASUS_DRW-24B3ST_B2D0CL222947
L:-100
I:15783031
E:ID_CDROM=1
E:SYSTEMD_MOUNT_DEVICE_BOUND=1
E:ID_CDROM_CD=1
E:ID_CDROM_CD_R=1
E:ID_CDROM_CD_RW=1
E:ID_CDROM_DVD=1
E:ID_CDROM_DVD_R=1
E:ID_CDROM_DVD_RW=1
E:ID_CDROM_DVD_RAM=1
E:ID_CDROM_DVD_PLUS_R=1
E:ID_CDROM_DVD_PLUS_RW=1
E:ID_CDROM_DVD_PLUS_R_DL=1
E:ID_CDROM_MRW=1
E:ID_CDROM_MRW_W=1
E:ID_ATA=1
E:ID_TYPE=cd
E:ID_BUS=ata
E:ID_MODEL=ASUS_DRW-24B3ST
E:ID_MODEL_ENC=ASUS\x20\x20\x20\x20DRW-24B3ST\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20
E:ID_REVISION=1.00
E:ID_SERIAL=ASUS_DRW-24B3ST_B2D0CL222947
E:ID_SERIAL_SHORT=B2D0CL222947
E:ID_ATA_SATA=1
E:ID_ATA_SATA_SIGNAL_RATE_GEN1=1
E:ID_PATH=pci-0000:00:1f.2-ata-2
E:ID_PATH_TAG=pci-0000_00_1f_2-ata-2
E:MPATH_SBIN_PATH=/sbin
E:ID_FS_TYPE=
E:ID_FOR_SEAT=block-pci-0000_00_1f_2-ata-2
G:uaccess
G:seat
G:systemd

If it looks like a disk drive, BOINC might be evaluating available disk space. We had a problem in Windows recently where, instead of simply reading file sizes, BOINC opened the file for reading and triggered a full virus scan.

Unless BOINC is installed in DVD I don't think it should be interested in how much disk space is available there. I can't really come up with good explanation though.

What distro this is?

Fedora FC26.

Ok. I'll try to put Fedora in a VM some day and hopefully see why it's poking files in /run.

Until then just ignore the error.