Revision 14d6d86c210aea1a83c19a8f6391ecabcbefed94 authored by Alexei Starovoitov on 19 November 2020, 18:45:55 UTC, committed by Alexei Starovoitov on 19 November 2020, 19:58:15 UTC
Daniel Xu says:

====================

6ae08ae3dea2 ("bpf: Add probe_read_{user, kernel} and probe_read_{user,
kernel}_str helpers") introduced a subtle bug where
bpf_probe_read_user_str() would potentially copy a few extra bytes after
the NUL terminator.

This issue is particularly nefarious when strings are used as map keys,
as seemingly identical strings can occupy multiple entries in a map.

This patchset fixes the issue and introduces a selftest to prevent
future regressions.

v6 -> v7:
* Add comments

v5 -> v6:
* zero-pad up to sizeof(unsigned long) after NUL

v4 -> v5:
* don't read potentially uninitialized memory

v3 -> v4:
* directly pass userspace pointer to prog
* test more strings of different length

v2 -> v3:
* set pid filter before attaching prog in selftest
* use long instead of int as bpf_probe_read_user_str() retval
* style changes

v1 -> v2:
* add Fixes: tag
* add selftest
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2 parent s 1fd6cee + c8a36ae
Raw File
xen.config
# global stuff - these enable us to allow some
# of the not so generic stuff below for xen
CONFIG_PARAVIRT=y
CONFIG_NET=y
CONFIG_NET_CORE=y
CONFIG_NETDEVICES=y
CONFIG_BLOCK=y
CONFIG_WATCHDOG=y
CONFIG_TARGET_CORE=y
CONFIG_SCSI=y
CONFIG_FB=y
CONFIG_INPUT_MISC=y
CONFIG_MEMORY_HOTPLUG=y
CONFIG_TTY=y
# Technically not required but otherwise produces
# pretty useless systems starting from allnoconfig
# You want TCP/IP and ELF binaries right?
CONFIG_INET=y
CONFIG_BINFMT_ELF=y
# generic config
CONFIG_XEN=y
CONFIG_XEN_DOM0=y
# backend drivers
CONFIG_XEN_BACKEND=y
CONFIG_XEN_BLKDEV_BACKEND=m
CONFIG_XEN_NETDEV_BACKEND=m
CONFIG_HVC_XEN=y
CONFIG_XEN_WDT=m
CONFIG_XEN_SCSI_BACKEND=m
# frontend drivers
CONFIG_XEN_FBDEV_FRONTEND=m
CONFIG_HVC_XEN_FRONTEND=y
CONFIG_INPUT_XEN_KBDDEV_FRONTEND=m
CONFIG_XEN_SCSI_FRONTEND=m
# others
CONFIG_XEN_BALLOON=y
CONFIG_XEN_SCRUB_PAGES=y
CONFIG_XEN_DEV_EVTCHN=m
CONFIG_XEN_BLKDEV_FRONTEND=m
CONFIG_XEN_NETDEV_FRONTEND=m
CONFIG_XENFS=m
CONFIG_XEN_COMPAT_XENFS=y
CONFIG_XEN_SYS_HYPERVISOR=y
CONFIG_XEN_XENBUS_FRONTEND=y
CONFIG_XEN_GNTDEV=m
CONFIG_XEN_GRANT_DEV_ALLOC=m
CONFIG_SWIOTLB_XEN=y
CONFIG_XEN_PRIVCMD=m
back to top