# 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 # 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 # Signed-off-by: Hillf Danton # Signed-off-by: David Howells # Tested-by: Sachin Sant # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version # < git log --format=%s --max-count=1 d41a3effbb53b1bcea41e328d16a4d046a508381 # < make -s -j 10 ARCH=powerpc O=/kisskb/build/linus_corenet64_smp_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- corenet64_smp_defconfig # make -s -j 10 ARCH=powerpc O=/kisskb/build/linus_corenet64_smp_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /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/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2591:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1852:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1465:5: warning: 'page' 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/fs/udf/unicode.c: In function 'udf_name_conv_char': /kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:248:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:228:19: note: 'i' 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] WARNING: vmlinux.o (.PPC.EMB.apuinfo): unexpected non-allocatable section. Did you forget to use "ax"/"aw" in a .S file? Note that for example contains section definitions for use in .S files. INFO: Uncompressed kernel (size 0x102cbe8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x1100000) Image Name: Linux-5.3.0-rc7-gd41a3effbb53 Created: Fri Sep 6 11:39:05 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 6793805 Bytes = 6634.58 KiB = 6.48 MiB Load Address: 00000000 Entry Point: 00000000 Completed OK # rm -rf /kisskb/build/linus_corenet64_smp_defconfig_powerpc-gcc4.6 # Build took: 0:02:10.891467