Buildresult: linus/um-allmodconfig/um-x86_64 built on Jan 9 2019, 14:17

kisskb

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Status:	OK
Date/Time:	Jan 9 2019, 14:17
Duration:	0:07:40.076870
Builder:	ka1
Revision:	fork: record start_time late (`7b55851367136b1efd84d98fea81ba57a98304cf)`
Target:	linus/um-allmodconfig/um-x86_64
Branch:	linus
Compiler:	um-x86_64 (x86_64-linux-gcc.br_real (Buildroot 2017.05) 5.4.0 / GNU ld (GNU Binutils) 2.27)
Config:	allmodconfig (download)
Log:	Download original Possible warnings (9) arch/um/kernel/skas/uaccess.c:62:10: warning: unused variable 'buf' [-Wunused-variable] arch/um/os-Linux/umid.c:138:2: warning: ISO C90 forbids variable length array 'file' [-Wvla] arch/um/os-Linux/umid.c:213:2: warning: ISO C90 forbids variable length array 'file' [-Wvla] arch/um/os-Linux/umid.c:388:2: warning: ISO C90 forbids variable length array 'dir' [-Wvla] kernel/bpf/verifier.c:5030:4: warning: 'prev_offset' may be used uninitialized in this function [-Wmaybe-uninitialized] kernel/cgroup/cgroup-v1.c:1263:3: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized] security/apparmor/policy_unpack.c:496:9: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized] lib/lz4/lz4hc_compress.c:579:1: warning: the frame size of 2144 bytes is larger than 2048 bytes [-Wframe-larger-than=] drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized] Full Log # git rev-parse -q --verify 7b55851367136b1efd84d98fea81ba57a98304cf^{commit} 7b55851367136b1efd84d98fea81ba57a98304cf already have revision, skipping fetch # git checkout -q -f -B kisskb 7b55851367136b1efd84d98fea81ba57a98304cf # git clean -qxdf # < git log -1 # commit 7b55851367136b1efd84d98fea81ba57a98304cf # Author: David Herrmann <dh.herrmann@gmail.com> # Date: Tue Jan 8 13:58:52 2019 +0100 # # fork: record start_time late # # This changes the fork(2) syscall to record the process start_time after # initializing the basic task structure but still before making the new # process visible to user-space. # # Technically, we could record the start_time anytime during fork(2). But # this might lead to scenarios where a start_time is recorded long before # a process becomes visible to user-space. For instance, with # userfaultfd(2) and TLS, user-space can delay the execution of fork(2) # for an indefinite amount of time (and will, if this causes network # access, or similar). # # By recording the start_time late, it much closer reflects the point in # time where the process becomes live and can be observed by other # processes. # # Lastly, this makes it much harder for user-space to predict and control # the start_time they get assigned. Previously, user-space could fork a # process and stall it in copy_thread_tls() before its pid is allocated, # but after its start_time is recorded. This can be misused to later-on # cycle through PIDs and resume the stalled fork(2) yielding a process # that has the same pid and start_time as a process that existed before. # This can be used to circumvent security systems that identify processes # by their pid+start_time combination. # # Even though user-space was always aware that start_time recording is # flaky (but several projects are known to still rely on start_time-based # identification), changing the start_time to be recorded late will help # mitigate existing attacks and make it much harder for user-space to # control the start_time a process gets assigned. # # Reported-by: Jann Horn <jannh@google.com> # Signed-off-by: Tom Gundersen <teg@jklm.no> # Signed-off-by: David Herrmann <dh.herrmann@gmail.com> # Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> # < /opt/cross/kisskb/fe-x86-64-core-i7-2017.05/bin/x86_64-linux-gcc --version # < /opt/cross/kisskb/fe-x86-64-core-i7-2017.05/bin/x86_64-linux-ld --version # < git log --format=%s --max-count=1 7b55851367136b1efd84d98fea81ba57a98304cf # < make -s -j 8 ARCH=um O=/kisskb/build/linus_um-allmodconfig_um-x86_64 CROSS_COMPILE=/opt/cross/kisskb/fe-x86-64-core-i7-2017.05/bin/x86_64-linux- SUBARCH=x86_64 allmodconfig # Added to kconfig CONFIG_STANDALONE=y # Added to kconfig CONFIG_KCOV=n # Added to kconfig CONFIG_GCC_PLUGINS=n # Added to kconfig CONFIG_GCC_PLUGIN_CYC_COMPLEXITY=n # Added to kconfig CONFIG_GCC_PLUGIN_SANCOV=n # Added to kconfig CONFIG_GCC_PLUGIN_LATENT_ENTROPY=n # Added to kconfig CONFIG_GCC_PLUGIN_STRUCTLEAK=n # Added to kconfig CONFIG_GCC_PLUGIN_RANDSTRUCT=n # Added to kconfig CONFIG_UML_NET=n # Added to kconfig CONFIG_UML_NET_ETHERTAP=n # Added to kconfig CONFIG_UML_NET_TUNTAP=n # Added to kconfig CONFIG_UML_NET_SLIP=n # Added to kconfig CONFIG_UML_NET_DAEMON=n # Added to kconfig CONFIG_UML_NET_VDE=n # Added to kconfig CONFIG_UML_NET_MCAST=n # Added to kconfig CONFIG_UML_NET_PCAP=n # Added to kconfig CONFIG_UML_NET_SLIRP=n # Added to kconfig CONFIG_GCOV_KERNEL=n # yes \n \| make -s -j 8 ARCH=um O=/kisskb/build/linus_um-allmodconfig_um-x86_64 CROSS_COMPILE=/opt/cross/kisskb/fe-x86-64-core-i7-2017.05/bin/x86_64-linux- SUBARCH=x86_64 oldconfig yes: standard output: Broken pipe # make -s -j 8 ARCH=um O=/kisskb/build/linus_um-allmodconfig_um-x86_64 CROSS_COMPILE=/opt/cross/kisskb/fe-x86-64-core-i7-2017.05/bin/x86_64-linux- SUBARCH=x86_64 /kisskb/src/arch/um/kernel/skas/uaccess.c: In function 'do_op_one_page': /kisskb/src/arch/um/kernel/skas/uaccess.c:62:10: warning: unused variable 'buf' [-Wunused-variable] jmp_buf buf; ^ /kisskb/src/arch/um/os-Linux/umid.c: In function 'is_umdir_used': /kisskb/src/arch/um/os-Linux/umid.c:138:2: warning: ISO C90 forbids variable length array 'file' [-Wvla] char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")]; ^ /kisskb/src/arch/um/os-Linux/umid.c: In function 'create_pid_file': /kisskb/src/arch/um/os-Linux/umid.c:213:2: warning: ISO C90 forbids variable length array 'file' [-Wvla] char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")]; ^ /kisskb/src/arch/um/os-Linux/umid.c: In function 'remove_umid_dir': /kisskb/src/arch/um/os-Linux/umid.c:388:2: warning: ISO C90 forbids variable length array 'dir' [-Wvla] char dir[strlen(uml_dir) + UMID_LEN + 1], err; ^ /kisskb/src/kernel/bpf/verifier.c: In function 'check_btf_info': /kisskb/src/kernel/bpf/verifier.c:5030:4: warning: 'prev_offset' may be used uninitialized in this function [-Wmaybe-uninitialized] verbose(env, ^ /kisskb/src/kernel/bpf/verifier.c:4965:38: note: 'prev_offset' was declared here u32 i, nfuncs, urec_size, min_size, prev_offset; ^ /kisskb/src/kernel/cgroup/cgroup-v1.c: In function 'cgroup1_mount': /kisskb/src/kernel/cgroup/cgroup-v1.c:1263:3: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized] percpu_ref_reinit(&root->cgrp.self.refcnt); ^ /kisskb/src/security/apparmor/policy_unpack.c: In function 'unpack_trans_table': /kisskb/src/security/apparmor/policy_unpack.c:496:9: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized] str[pos] = ':'; ^ /kisskb/src/lib/lz4/lz4hc_compress.c: In function 'LZ4HC_compress_generic': /kisskb/src/lib/lz4/lz4hc_compress.c:579:1: warning: the frame size of 2144 bytes is larger than 2048 bytes [-Wframe-larger-than=] } ^ /kisskb/src/drivers/i2c/i2c-core-base.c: In function 'i2c_generic_scl_recovery': /kisskb/src/drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized] if (ret == -EOPNOTSUPP) ^ LINK linux Completed OK # rm -rf /kisskb/build/linus_um-allmodconfig_um-x86_64 # Build took: 0:07:40.076870

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