Revision 633593a808980f82d251d0ca89730d8bb8b0220c authored by Eric Dumazet on 10 March 2022, 00:11:45 UTC, committed by Jakub Kicinski on 10 March 2022, 22:46:42 UTC
syzbot reported a kernel infoleak [1] of 4 bytes. After analysis, it turned out r->idiag_expires is not initialized if inet_sctp_diag_fill() calls inet_diag_msg_common_fill() Make sure to clear idiag_timer/idiag_retrans/idiag_expires and let inet_diag_msg_sctpasoc_fill() fill them again if needed. [1] BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:121 [inline] BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:154 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668 instrument_copy_to_user include/linux/instrumented.h:121 [inline] copyout lib/iov_iter.c:154 [inline] _copy_to_iter+0x6ef/0x25a0 lib/iov_iter.c:668 copy_to_iter include/linux/uio.h:162 [inline] simple_copy_to_iter+0xf3/0x140 net/core/datagram.c:519 __skb_datagram_iter+0x2d5/0x11b0 net/core/datagram.c:425 skb_copy_datagram_iter+0xdc/0x270 net/core/datagram.c:533 skb_copy_datagram_msg include/linux/skbuff.h:3696 [inline] netlink_recvmsg+0x669/0x1c80 net/netlink/af_netlink.c:1977 sock_recvmsg_nosec net/socket.c:948 [inline] sock_recvmsg net/socket.c:966 [inline] __sys_recvfrom+0x795/0xa10 net/socket.c:2097 __do_sys_recvfrom net/socket.c:2115 [inline] __se_sys_recvfrom net/socket.c:2111 [inline] __x64_sys_recvfrom+0x19d/0x210 net/socket.c:2111 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Uninit was created at: slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3247 [inline] __kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4975 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0x545/0xf90 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1158 [inline] netlink_dump+0x3e5/0x16c0 net/netlink/af_netlink.c:2248 __netlink_dump_start+0xcf8/0xe90 net/netlink/af_netlink.c:2373 netlink_dump_start include/linux/netlink.h:254 [inline] inet_diag_handler_cmd+0x2e7/0x400 net/ipv4/inet_diag.c:1341 sock_diag_rcv_msg+0x24a/0x620 netlink_rcv_skb+0x40c/0x7e0 net/netlink/af_netlink.c:2494 sock_diag_rcv+0x63/0x80 net/core/sock_diag.c:277 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x1093/0x1360 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x14d9/0x1720 net/netlink/af_netlink.c:1919 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg net/socket.c:725 [inline] sock_write_iter+0x594/0x690 net/socket.c:1061 do_iter_readv_writev+0xa7f/0xc70 do_iter_write+0x52c/0x1500 fs/read_write.c:851 vfs_writev fs/read_write.c:924 [inline] do_writev+0x645/0xe00 fs/read_write.c:967 __do_sys_writev fs/read_write.c:1040 [inline] __se_sys_writev fs/read_write.c:1037 [inline] __x64_sys_writev+0xe5/0x120 fs/read_write.c:1037 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x44/0xae Bytes 68-71 of 2508 are uninitialized Memory access of size 2508 starts at ffff888114f9b000 Data copied to user address 00007f7fe09ff2e0 CPU: 1 PID: 3478 Comm: syz-executor306 Not tainted 5.17.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Link: https://lore.kernel.org/r/20220310001145.297371-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Makefile.host
# SPDX-License-Identifier: GPL-2.0
# LEX
# ---------------------------------------------------------------------------
quiet_cmd_flex = LEX $@
cmd_flex = $(LEX) -o$@ -L $<
$(obj)/%.lex.c: $(src)/%.l FORCE
$(call if_changed,flex)
# YACC
# ---------------------------------------------------------------------------
quiet_cmd_bison = YACC $(basename $@).[ch]
cmd_bison = $(YACC) -o $(basename $@).c --defines=$(basename $@).h -t -l $<
$(obj)/%.tab.c $(obj)/%.tab.h: $(src)/%.y FORCE
$(call if_changed,bison)
# ==========================================================================
# Building binaries on the host system
# Binaries are used during the compilation of the kernel, for example
# to preprocess a data file.
#
# Both C and C++ are supported, but preferred language is C for such utilities.
#
# Sample syntax (see Documentation/kbuild/makefiles.rst for reference)
# hostprogs := bin2hex
# Will compile bin2hex.c and create an executable named bin2hex
#
# hostprogs := lxdialog
# lxdialog-objs := checklist.o lxdialog.o
# Will compile lxdialog.c and checklist.c, and then link the executable
# lxdialog, based on checklist.o and lxdialog.o
#
# hostprogs := qconf
# qconf-cxxobjs := qconf.o
# qconf-objs := menu.o
# Will compile qconf as a C++ program, and menu as a C program.
# They are linked as C++ code to the executable qconf
# C code
# Executables compiled from a single .c file
host-csingle := $(foreach m,$(hostprogs), \
$(if $($(m)-objs)$($(m)-cxxobjs),,$(m)))
# C executables linked based on several .o files
host-cmulti := $(foreach m,$(hostprogs),\
$(if $($(m)-cxxobjs),,$(if $($(m)-objs),$(m))))
# Object (.o) files compiled from .c files
host-cobjs := $(sort $(foreach m,$(hostprogs),$($(m)-objs)))
# C++ code
# C++ executables compiled from at least one .cc file
# and zero or more .c files
host-cxxmulti := $(foreach m,$(hostprogs),$(if $($(m)-cxxobjs),$(m)))
# C++ Object (.o) files compiled from .cc files
host-cxxobjs := $(sort $(foreach m,$(host-cxxmulti),$($(m)-cxxobjs)))
host-csingle := $(addprefix $(obj)/,$(host-csingle))
host-cmulti := $(addprefix $(obj)/,$(host-cmulti))
host-cobjs := $(addprefix $(obj)/,$(host-cobjs))
host-cxxmulti := $(addprefix $(obj)/,$(host-cxxmulti))
host-cxxobjs := $(addprefix $(obj)/,$(host-cxxobjs))
#####
# Handle options to gcc. Support building with separate output directory
_hostc_flags = $(KBUILD_HOSTCFLAGS) $(HOST_EXTRACFLAGS) \
$(HOSTCFLAGS_$(target-stem).o)
_hostcxx_flags = $(KBUILD_HOSTCXXFLAGS) $(HOST_EXTRACXXFLAGS) \
$(HOSTCXXFLAGS_$(target-stem).o)
# $(objtree)/$(obj) for including generated headers from checkin source files
ifeq ($(KBUILD_EXTMOD),)
ifdef building_out_of_srctree
_hostc_flags += -I $(objtree)/$(obj)
_hostcxx_flags += -I $(objtree)/$(obj)
endif
endif
hostc_flags = -Wp,-MMD,$(depfile) $(_hostc_flags)
hostcxx_flags = -Wp,-MMD,$(depfile) $(_hostcxx_flags)
#####
# Compile programs on the host
# Create executable from a single .c file
# host-csingle -> Executable
quiet_cmd_host-csingle = HOSTCC $@
cmd_host-csingle = $(HOSTCC) $(hostc_flags) $(KBUILD_HOSTLDFLAGS) -o $@ $< \
$(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
$(host-csingle): $(obj)/%: $(src)/%.c FORCE
$(call if_changed_dep,host-csingle)
# Link an executable based on list of .o files, all plain c
# host-cmulti -> executable
quiet_cmd_host-cmulti = HOSTLD $@
cmd_host-cmulti = $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -o $@ \
$(addprefix $(obj)/, $($(target-stem)-objs)) \
$(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
$(host-cmulti): FORCE
$(call if_changed,host-cmulti)
$(call multi_depend, $(host-cmulti), , -objs)
# Create .o file from a single .c file
# host-cobjs -> .o
quiet_cmd_host-cobjs = HOSTCC $@
cmd_host-cobjs = $(HOSTCC) $(hostc_flags) -c -o $@ $<
$(host-cobjs): $(obj)/%.o: $(src)/%.c FORCE
$(call if_changed_dep,host-cobjs)
# Link an executable based on list of .o files, a mixture of .c and .cc
# host-cxxmulti -> executable
quiet_cmd_host-cxxmulti = HOSTLD $@
cmd_host-cxxmulti = $(HOSTCXX) $(KBUILD_HOSTLDFLAGS) -o $@ \
$(foreach o,objs cxxobjs,\
$(addprefix $(obj)/, $($(target-stem)-$(o)))) \
$(KBUILD_HOSTLDLIBS) $(HOSTLDLIBS_$(target-stem))
$(host-cxxmulti): FORCE
$(call if_changed,host-cxxmulti)
$(call multi_depend, $(host-cxxmulti), , -objs -cxxobjs)
# Create .o file from a single .cc (C++) file
quiet_cmd_host-cxxobjs = HOSTCXX $@
cmd_host-cxxobjs = $(HOSTCXX) $(hostcxx_flags) -c -o $@ $<
$(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE
$(call if_changed_dep,host-cxxobjs)
targets += $(host-csingle) $(host-cmulti) $(host-cobjs) \
$(host-cxxmulti) $(host-cxxobjs)
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