# git rev-parse -q --verify 4641f73de643289a4caa835cbe37061754e57304^{commit} 4641f73de643289a4caa835cbe37061754e57304 already have revision, skipping fetch # git checkout -q -f -B kisskb 4641f73de643289a4caa835cbe37061754e57304 # git clean -qxdf # < git log -1 # commit 4641f73de643289a4caa835cbe37061754e57304 # Author: He Ying # Date: Thu Jan 20 20:44:18 2022 -0500 # # powerpc/kasan: Silence KASAN warnings in __get_wchan() # # The following KASAN warning was reported in our kernel. # # BUG: KASAN: stack-out-of-bounds in get_wchan+0x188/0x250 # Read of size 4 at addr d216f958 by task ps/14437 # # CPU: 3 PID: 14437 Comm: ps Tainted: G O 5.10.0 #1 # Call Trace: # [daa63858] [c0654348] dump_stack+0x9c/0xe4 (unreliable) # [daa63888] [c035cf0c] print_address_description.constprop.3+0x8c/0x570 # [daa63908] [c035d6bc] kasan_report+0x1ac/0x218 # [daa63948] [c00496e8] get_wchan+0x188/0x250 # [daa63978] [c0461ec8] do_task_stat+0xce8/0xe60 # [daa63b98] [c0455ac8] proc_single_show+0x98/0x170 # [daa63bc8] [c03cab8c] seq_read_iter+0x1ec/0x900 # [daa63c38] [c03cb47c] seq_read+0x1dc/0x290 # [daa63d68] [c037fc94] vfs_read+0x164/0x510 # [daa63ea8] [c03808e4] ksys_read+0x144/0x1d0 # [daa63f38] [c005b1dc] ret_from_syscall+0x0/0x38 # --- interrupt: c00 at 0x8fa8f4 # LR = 0x8fa8cc # # The buggy address belongs to the page: # page:98ebcdd2 refcount:0 mapcount:0 mapping:00000000 index:0x2 pfn:0x1216f # flags: 0x0() # raw: 00000000 00000000 01010122 00000000 00000002 00000000 ffffffff 00000000 # raw: 00000000 # page dumped because: kasan: bad access detected # # Memory state around the buggy address: # d216f800: 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00 00 00 # d216f880: f2 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # >d216f900: 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 # ^ # d216f980: f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 00 00 # d216fa00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 # # After looking into this issue, I find the buggy address belongs # to the task stack region. It seems KASAN has something wrong. # I look into the code of __get_wchan in x86 architecture and # find the same issue has been resolved by the commit # f7d27c35ddff ("x86/mm, kasan: Silence KASAN warnings in get_wchan()"). # The solution could be applied to powerpc architecture too. # # As Andrey Ryabinin said, get_wchan() is racy by design, it may # access volatile stack of running task, thus it may access # redzone in a stack frame and cause KASAN to warn about this. # # Use READ_ONCE_NOCHECK() to silence these warnings. # # Reported-by: Wanming Hu # Signed-off-by: He Ying # Signed-off-by: Chen Jingwen # Reviewed-by: Kees Cook # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20220121014418.155675-1-heying24@huawei.com # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 4641f73de643289a4caa835cbe37061754e57304 # < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64_book3e_allmodconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- ppc64_book3e_allmodconfig # < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64_book3e_allmodconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64_book3e_allmodconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc64_book3e_allmodconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux- /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@ffe00000/mdio@24000/ethernet-phy@0:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@ffe00000/mdio@24000/ethernet-phy@1:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@fffe00000/mdio@24000/ethernet-phy@0:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@fffe00000/mdio@24000/ethernet-phy@1:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/kmcoge4.dts:196.23-198.4: Warning (pci_bridge): /pcie@ffe201000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p2041si-post.dtsi:87.7-113.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p2041si-post.dtsi:97.9-112.4: Warning (pci_bridge): /pcie@ffe201000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/kmcoge4.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/ppa8548.dts:34.22-37.4: Warning (pci_bridge): /pci@fe0008000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8548si-post.dtsi:43.7-51.3 arch/powerpc/boot/dts/fsl/kmcoge4.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/kmcoge4.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/ppa8548.dts:39.22-42.4: Warning (pci_bridge): /pci@fe0009000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8548si-post.dtsi:54.7-62.3 /kisskb/src/arch/powerpc/boot/dts/fsl/ppa8548.dts:44.23-47.4: Warning (pci_bridge): /pcie@fe000a000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8548si-post.dtsi:65.7-90.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8548si-post.dtsi:74.9-89.4: Warning (pci_bridge): /pcie@fe000a000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/ppa8548.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/ppa8548.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/ppa8548.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/p1020rdb-pd.dts:189.11-193.6: Warning (spi_bus_reg): /soc@ffe00000/spi@7000/slic@0: SPI bus unit address format error, expected "1" /kisskb/src/arch/powerpc/boot/dts/fsl/p1020rdb-pd.dts:195.11-199.6: Warning (spi_bus_reg): /soc@ffe00000/spi@7000/slic@1: SPI bus unit address format error, expected "2" /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8555cds.dts:341.15-350.5: Warning (pci_device_reg): /pci@e0008000/i8259@19000: PCI unit address format error, expected "12,0" /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8555cds.dts:330.3-21: Warning (pci_device_bus_num): /pci@e0008000/i8259@19000:bus-range: PCI bus number 1 out of range, expected (0 - 0) /kisskb/src/arch/powerpc/boot/dts/mpc5121.dtsi:457.13-466.5: Warning (spi_bus_bridge): /soc@80000000/psc@11900: node name for SPI buses should be 'spi' also defined at /kisskb/src/arch/powerpc/boot/dts/pdm360ng.dts:172.13-185.5 arch/powerpc/boot/dts/pdm360ng.dtb: Warning (spi_bus_reg): Failed prerequisite 'spi_bus_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@ffe00000/mdio@24000/ethernet-phy@0:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@ffe00000/mdio@24000/ethernet-phy@1:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/gef_sbc610.dts:209.22-211.4: Warning (pci_bridge): /pcie@fef09000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:119.7-144.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:129.9-143.4: Warning (pci_bridge): /pcie@fef09000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/gef_sbc610.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/gef_sbc610.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/gef_sbc610.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/bluestone.dts:272.13-277.7: Warning (i2c_bus_reg): /plb/opb/i2c@ef600700/sttm@4C: I2C bus unit address format error, expected "4c" /kisskb/src/arch/powerpc/boot/dts/mgcoge.dts:230.14-234.7: Warning (spi_bus_reg): /soc@f0000000/cpm@119c0/spi@11aa0/ds3106@1: SPI bus unit address format error, expected "0" /kisskb/src/arch/powerpc/boot/dts/fsl/gef_ppc9a.dts:211.22-213.4: Warning (pci_bridge): /pcie@fef09000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:119.7-144.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:129.9-143.4: Warning (pci_bridge): /pcie@fef09000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/gef_ppc9a.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/gef_ppc9a.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/gef_ppc9a.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/oca4080.dts:132.23-134.4: Warning (pci_bridge): /pcie@ffe200000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:58.7-84.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:68.9-83.4: Warning (pci_bridge): /pcie@ffe200000/pcie@0: missing ranges for PCI bridge (or not a bridge) /kisskb/src/arch/powerpc/boot/dts/fsl/oca4080.dts:136.23-138.4: Warning (pci_bridge): /pcie@ffe201000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:87.7-113.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:97.9-112.4: Warning (pci_bridge): /pcie@ffe201000/pcie@0: missing ranges for PCI bridge (or not a bridge) /kisskb/src/arch/powerpc/boot/dts/fsl/oca4080.dts:140.23-142.4: Warning (pci_bridge): /pcie@ffe202000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:116.7-142.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p4080si-post.dtsi:126.9-141.4: Warning (pci_bridge): /pcie@ffe202000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/oca4080.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/oca4080.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/oca4080.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@fffe00000/mdio@24000/ethernet-phy@0:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/fsl/pq3-mpic.dtsi:38.2-25: Warning (interrupts_property): /soc@fffe00000/mdio@24000/ethernet-phy@1:#interrupt-cells: size is (8), expected multiple of 16 /kisskb/src/arch/powerpc/boot/dts/stxssa8555.dts:340.15-349.5: Warning (pci_device_reg): /pci@e0008000/i8259@19000: PCI unit address format error, expected "12,0" /kisskb/src/arch/powerpc/boot/dts/stxssa8555.dts:329.3-21: Warning (pci_device_bus_num): /pci@e0008000/i8259@19000:bus-range: PCI bus number 1 out of range, expected (0 - 0) /kisskb/src/arch/powerpc/boot/dts/fsl/p2020rdb-pc_36b.dts:59.23-62.4: Warning (pci_bridge): /pcie@fffe08000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:100.7-126.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:109.9-125.4: Warning (pci_bridge): /pcie@fffe08000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/p2020rdb-pc_36b.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb-pc_36b.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb-pc_36b.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/p2020rdb-pc_32b.dts:59.22-62.4: Warning (pci_bridge): /pcie@ffe08000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:100.7-126.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:109.9-125.4: Warning (pci_bridge): /pcie@ffe08000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/p2020rdb-pc_32b.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb-pc_32b.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb-pc_32b.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/mpc8610_hpcd.dts:420.3-21: Warning (pci_device_bus_num): /pcie@e000a000/pcie@0:bus-range: PCI bus number 0 out of range, expected (1 - 3) /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8541cds.dts:341.15-350.5: Warning (pci_device_reg): /pci@e0008000/i8259@19000: PCI unit address format error, expected "12,0" /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8541cds.dts:330.3-21: Warning (pci_device_bus_num): /pci@e0008000/i8259@19000:bus-range: PCI bus number 1 out of range, expected (0 - 0) /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:135.22-137.4: Warning (pci_bridge): /pcie@f1008000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:92.7-117.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:102.9-116.4: Warning (pci_bridge): /pcie@f1008000/pcie@0: missing ranges for PCI bridge (or not a bridge) /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:139.22-141.4: Warning (pci_bridge): /pcie@f1009000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:119.7-144.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:129.9-143.4: Warning (pci_bridge): /pcie@f1009000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/mvme7100.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/mvme7100.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/mvme7100.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:30.11-32.6: Warning (i2c_bus_reg): /soc@f1000000/i2c@3000/rtc@68: missing or empty reg property /kisskb/src/arch/powerpc/boot/dts/fsl/p2020rdb.dts:251.22-254.4: Warning (pci_bridge): /pcie@ffe08000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:43.7-68.3 /kisskb/src/arch/powerpc/boot/dts/fsl/p2020si-post.dtsi:52.9-67.4: Warning (pci_bridge): /pcie@ffe08000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/p2020rdb.dtb: Warning (unit_address_format): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb.dtb: Warning (pci_device_reg): Failed prerequisite 'pci_bridge' arch/powerpc/boot/dts/fsl/p2020rdb.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/mpc5121.dtsi:397.13-406.5: Warning (spi_bus_bridge): /soc@80000000/psc@11400: node name for SPI buses should be 'spi' also defined at /kisskb/src/arch/powerpc/boot/dts/ac14xx.dts:305.19-326.5 /kisskb/src/arch/powerpc/boot/dts/mpc5121.dtsi:409.13-418.5: Warning (spi_bus_bridge): /soc@80000000/psc@11500: node name for SPI buses should be 'spi' also defined at /kisskb/src/arch/powerpc/boot/dts/ac14xx.dts:329.19-344.5 arch/powerpc/boot/dts/ac14xx.dtb: Warning (spi_bus_reg): Failed prerequisite 'spi_bus_bridge' Completed OK # rm -rf /kisskb/build/powerpc-next_ppc64_book3e_allmodconfig_powerpc-gcc11 # Build took: 0:07:58.843497