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Revision 9c1c2b35f1d94de8325344c2777d7ee67492db3b authored by Jeff Layton on 03 April 2019, 17:16:01 UTC, committed by Ilya Dryomov on 21 January 2020, 18:02:37 UTC 
ceph: hold extra reference to r_parent over life of request
 
Currently, we just assume that it will stick around by virtue of the
submitter's reference, but later patches will allow the syscall to
return early and we can't rely on that reference at that point.

While I'm not aware of any reports of it, Xiubo pointed out that this
may fix a use-after-free.  If the wait for a reply times out or is
canceled via signal, and then the reply comes in after the syscall
returns, the client can end up trying to access r_parent without a
reference.

Take an extra reference to the inode when setting r_parent and release
it when releasing the request.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
1 parent def9d27
Raw File
Makefile.headersinst 
# SPDX-License-Identifier: GPL-2.0
# ==========================================================================
# Installing headers
#
# All headers under include/uapi, include/generated/uapi,
# arch/<arch>/include/uapi and arch/<arch>/include/generated/uapi are
# exported.
# They are preprocessed to remove __KERNEL__ section of the file.
#
# ==========================================================================

PHONY := __headers
__headers:

include scripts/Kbuild.include

src := $(srctree)/$(obj)
gen := $(objtree)/$(subst include/,include/generated/,$(obj))
dst := usr/include

-include $(src)/Kbuild

# $(filter %/, ...) is a workaround for GNU Make <= 4.2.1, where
# $(wildcard $(src)/*/) contains not only directories but also regular files.
src-subdirs := $(patsubst $(src)/%/,%,$(filter %/, $(wildcard $(src)/*/)))
gen-subdirs := $(patsubst $(gen)/%/,%,$(filter %/, $(wildcard $(gen)/*/)))
all-subdirs := $(sort $(src-subdirs) $(gen-subdirs))

src-headers := $(if $(src-subdirs), $(shell cd $(src) && find $(src-subdirs) -name '*.h'))
src-headers := $(filter-out $(no-export-headers), $(src-headers))
gen-headers := $(if $(gen-subdirs), $(shell cd $(gen) && find $(gen-subdirs) -name '*.h'))
gen-headers := $(filter-out $(no-export-headers), $(gen-headers))

# If the same header is exported from source and generated directories,
# the former takes precedence, but this should be warned.
duplicated := $(filter $(gen-headers), $(src-headers))
$(if $(duplicated), $(warning duplicated header export: $(duplicated)))

gen-headers := $(filter-out $(duplicated), $(gen-headers))

# Add dst path prefix
all-subdirs := $(addprefix $(dst)/, $(all-subdirs))
src-headers := $(addprefix $(dst)/, $(src-headers))
gen-headers := $(addprefix $(dst)/, $(gen-headers))
all-headers := $(src-headers) $(gen-headers)

# Work out what needs to be removed
old-subdirs := $(wildcard $(all-subdirs))
old-headers := $(if $(old-subdirs),$(shell find $(old-subdirs) -name '*.h'))
unwanted    := $(filter-out $(all-headers), $(old-headers))

# Create directories
existing-dirs := $(sort $(dir $(old-headers)))
wanted-dirs   := $(sort $(dir $(all-headers)))
new-dirs      := $(filter-out $(existing-dirs), $(wanted-dirs))
$(if $(new-dirs), $(shell mkdir -p $(new-dirs)))

# Rules
quiet_cmd_install = HDRINST $@
      cmd_install = $(CONFIG_SHELL) $(srctree)/scripts/headers_install.sh $< $@

$(src-headers): $(dst)/%.h: $(src)/%.h $(srctree)/scripts/headers_install.sh FORCE
	$(call if_changed,install)

$(gen-headers): $(dst)/%.h: $(gen)/%.h $(srctree)/scripts/headers_install.sh FORCE
	$(call if_changed,install)

quiet_cmd_remove = REMOVE  $(unwanted)
      cmd_remove = rm -f $(unwanted)

__headers: $(all-headers)
ifneq ($(unwanted),)
	$(call cmd,remove)
endif
	@:

existing-headers := $(filter $(old-headers), $(all-headers))

-include $(foreach f,$(existing-headers),$(dir $(f)).$(notdir $(f)).cmd)

PHONY += FORCE
FORCE:

.PHONY: $(PHONY)
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