# 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/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-gcc --version
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-ld --version
# < git log --format=%s --max-count=1 d41a3effbb53b1bcea41e328d16a4d046a508381
# < make -s -j 8 ARCH=arm O=/kisskb/build/linus_shmobile_defconfig_arm CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-  shmobile_defconfig
# make -s -j 8 ARCH=arm O=/kisskb/build/linus_shmobile_defconfig_arm CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-  
/kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl':
/kisskb/src/kernel/printk/printk.c:194:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/rcu/srcutree.c: In function 'init_srcu_struct_fields':
/kisskb/src/kernel/rcu/srcutree.c:140:32: warning: 'levelspread[<U53c0>]' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/rcu/srcutree.c:88:6: note: 'levelspread[<U53c0>]' was declared here
/kisskb/src/ipc/shm.c: In function 'ksys_shmdt':
/kisskb/src/ipc/shm.c:1712:59: warning: 'file' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/proc/inode.c: In function 'proc_reg_open':
/kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/proc/inode.c:338:21: note: 'pdeo' was declared here
/kisskb/src/net/core/gen_stats.c: In function '__gnet_stats_copy_basic':
/kisskb/src/net/core/gen_stats.c:157:19: warning: 'seq' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/sound/core/pcm_iec958.c: In function 'create_iec958_consumer':
/kisskb/src/sound/core/pcm_iec958.c:77:9: warning: 'ws' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/net/core/dev.c: In function 'validate_xmit_skb_list':
/kisskb/src/net/core/dev.c:3407:15: warning: 'tail' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/lib/rhashtable.c: In function 'rht_deferred_worker':
/kisskb/src/include/linux/rhashtable.h:110:10: warning: 'next' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/lib/rhashtable.c:222:28: note: 'next' was declared here
/kisskb/src/drivers/gpio/gpiolib-of.c: In function 'of_gpiochip_add':
/kisskb/src/drivers/gpio/gpiolib-of.c:505:8: warning: 'dflags' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/gpio/gpiolib-of.c:491:19: note: 'dflags' was declared here
/kisskb/src/drivers/gpio/gpiolib-of.c:505:8: warning: 'lflags' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/gpio/gpiolib-of.c:490:16: note: 'lflags' was declared here
/kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c: In function 'sh_mobile_i2c_isr':
/kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:399:26: warning: 'data' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:372:16: note: 'data' was declared here
/kisskb/src/drivers/gpu/drm/drm_dp_mst_topology.c: In function 'drm_dp_sideband_msg_build':
/kisskb/src/drivers/gpu/drm/drm_dp_mst_topology.c:424:23: warning: 'hdrlen' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/gpu/drm/drm_atomic.c: In function 'drm_atomic_check_only':
/kisskb/src/drivers/gpu/drm/drm_atomic.c:426:38: warning: 'crtc_state' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/gpu/drm/drm_atomic.c:405:25: note: 'crtc_state' was declared here
/kisskb/src/drivers/usb/core/devio.c: In function 'async_completed':
/kisskb/src/drivers/usb/core/devio.c:613:23: warning: 'errno' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/usb/host/xhci-debugfs.c: In function 'xhci_ring_open':
/kisskb/src/drivers/usb/host/xhci-debugfs.c:246:20: warning: 'f_map' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/usb/host/xhci-debugfs.c: In function 'xhci_context_open':
/kisskb/src/drivers/usb/host/xhci-debugfs.c:327:20: warning: 'f_map' may be used uninitialized in this function [-Wuninitialized]
Completed OK
# rm -rf /kisskb/build/linus_shmobile_defconfig_arm
# Build took: 0:01:30.388167