# git rev-parse -q --verify d41a3effbb53b1bcea41e328d16a4d046a508381^{commit}
d41a3effbb53b1bcea41e328d16a4d046a508381
already have revision, skipping fetch
# git checkout -q -f -B kisskb d41a3effbb53b1bcea41e328d16a4d046a508381
# git clean -qxdf
# < git log -1
# commit d41a3effbb53b1bcea41e328d16a4d046a508381
# Author: Hillf Danton <hdanton@sina.com>
# Date:   Mon Sep 2 13:37:29 2019 +0100
# 
#     keys: Fix missing null pointer check in request_key_auth_describe()
#     
#     If a request_key authentication token key gets revoked, there's a window in
#     which request_key_auth_describe() can see it with a NULL payload - but it
#     makes no check for this and something like the following oops may occur:
#     
#             BUG: Kernel NULL pointer dereference at 0x00000038
#             Faulting instruction address: 0xc0000000004ddf30
#             Oops: Kernel access of bad area, sig: 11 [#1]
#             ...
#             NIP [...] request_key_auth_describe+0x90/0xd0
#             LR [...] request_key_auth_describe+0x54/0xd0
#             Call Trace:
#             [...] request_key_auth_describe+0x54/0xd0 (unreliable)
#             [...] proc_keys_show+0x308/0x4c0
#             [...] seq_read+0x3d0/0x540
#             [...] proc_reg_read+0x90/0x110
#             [...] __vfs_read+0x3c/0x70
#             [...] vfs_read+0xb4/0x1b0
#             [...] ksys_read+0x7c/0x130
#             [...] system_call+0x5c/0x70
#     
#     Fix this by checking for a NULL pointer when describing such a key.
#     
#     Also make the read routine check for a NULL pointer to be on the safe side.
#     
#     [DH: Modified to not take already-held rcu lock and modified to also check
#      in the read routine]
#     
#     Fixes: 04c567d9313e ("[PATCH] Keys: Fix race between two instantiators of a key")
#     Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
#     Signed-off-by: Hillf Danton <hdanton@sina.com>
#     Signed-off-by: David Howells <dhowells@redhat.com>
#     Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/mips-linux/bin/mips-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/mips-linux/bin/mips-linux-ld --version
# < git log --format=%s --max-count=1 d41a3effbb53b1bcea41e328d16a4d046a508381
# < make -s -j 8 ARCH=mips O=/kisskb/build/linus_mips-allnoconfig_mips-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/mips-linux/bin/mips-linux-  allnoconfig
# make -s -j 8 ARCH=mips O=/kisskb/build/linus_mips-allnoconfig_mips-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/mips-linux/bin/mips-linux-  
<stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
FIT description: Linux 5.3.0-rc7+
Created:         Fri Sep  6 12:01:55 2019
 Image 0 (kernel@0)
  Description:  Linux 5.3.0-rc7+
  Created:      Fri Sep  6 12:01:55 2019
  Type:         Kernel Image
  Compression:  gzip compressed
  Data Size:    654178 Bytes = 638.85 KiB = 0.62 MiB
  Architecture: MIPS
  OS:           Linux
  Load Address: 0x80100000
  Entry Point:  0x80225ea0
  Hash algo:    sha1
  Hash value:   2d48d0171566662fc8d2de9988f69ca50694864c
 Default Configuration: 'conf@default'
 Configuration 0 (conf@default)
  Description:  Generic Linux kernel
  Kernel:       kernel@0
Completed OK
# rm -rf /kisskb/build/linus_mips-allnoconfig_mips-gcc8
# Build took: 0:00:25.270714