Pull misc uaccess updates from Al Viro:
"Assorted uaccess patches for this cycle - the stuff that didn't fit
into thematic series"
* 'uaccess.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
bpf: make bpf_check_uarg_tail_zero() use check_zeroed_user()
x86: kvm_hv_set_msr(): use __put_user() instead of 32bit __clear_user()
user_regset_copyout_zero(): use clear_user()
TEST_ACCESS_OK _never_ had been checked anywhere
x86: switch cp_stat64() to unsafe_put_user()
binfmt_flat: don't use __put_user()
binfmt_elf_fdpic: don't use __... uaccess primitives
binfmt_elf: don't bother with __{put,copy_to}_user()
pselect6() and friends: take handling the combined 6th/7th args into helper
load_flat_file works on user addresses. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Greg Ungerer <gerg@linux-m68k.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Link: http://lkml.kernel.org/r/20200515143646.3857579-28-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
... and check the return value Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
There is and has been for a very long time been a lot more going on in flush_old_exec than just flushing the old state. After the movement of code from setup_new_exec there is a whole lot more going on than just flushing the old executables state. Rename flush_old_exec to begin_new_exec to more accurately reflect what this function does. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The two functions are now always called one right after the other so merge them together to make future maintenance easier. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
In 2016 Linus moved install_exec_creds immediately after
setup_new_exec, in binfmt_elf as a cleanup and as part of closing a
potential information leak.
Perform the same cleanup for the other binary formats.
Different binary formats doing the same things the same way makes exec
easier to reason about and easier to maintain.
Greg Ungerer reports:
> I tested the the whole series on non-MMU m68k and non-MMU arm
> (exercising binfmt_flat) and it all tested out with no problems,
> so for the binfmt_flat changes:
Tested-by: Greg Ungerer <gerg@linux-m68k.org>
Ref: 9f834ec18def ("binfmt_elf: switch to new creds when switching to new mm")
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Fixes gcc '-Wunused-but-set-variable' warning: fs/binfmt_flat.c: In function load_flat_file: fs/binfmt_flat.c:419:16: warning: variable inode set but not used [-Wunused-but-set-variable] It's never used and can be removed. Link: http://lkml.kernel.org/r/20190525125341.9844-1-yuehaibing@huawei.com Signed-off-by: YueHaibing <yuehaibing@huawei.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull m68nommu updates from Greg Ungerer: "A series of cleanups for the FLAT format binary loader, binfmt_flat, from Christoph. The end goal is to support no-MMU on RISC-V, and the last patch enables that" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu: riscv: add binfmt_flat support binfmt_flat: don't offset the data start binfmt_flat: move the MAX_SHARED_LIBS definition to binfmt_flat.c binfmt_flat: remove the persistent argument from flat_get_addr_from_rp binfmt_flat: provide an asm-generic/flat.h binfmt_flat: make support for old format binaries optional binfmt_flat: add a ARCH_HAS_BINFMT_FLAT option binfmt_flat: add endianess annotations binfmt_flat: use fixed size type for the on-disk format binfmt_flat: consolidate two version of flat_v2_reloc_t binfmt_flat: remove the unused OLD_FLAT_FLAG_RAM definition binfmt_flat: remove the uapi <linux/flat.h> header binfmt_flat: replace flat_argvp_envp_on_stack with a Kconfig variable binfmt_flat: remove flat_old_ram_flag binfmt_flat: provide a default version of flat_get_relocate_addr binfmt_flat: remove flat_set_persistent binfmt_flat: remove flat_reloc_valid
load_flat_shared_library() is broken: It only calls load_flat_file() if
prepare_binprm() returns zero, but prepare_binprm() returns the number of
bytes read - so this only happens if the file is empty.
Instead, call into load_flat_file() if the number of bytes read is
non-negative. (Even if the number of bytes is zero - in that case,
load_flat_file() will see nullbytes and return a nice -ENOEXEC.)
In addition, remove the code related to bprm creds and stop using
prepare_binprm() - this code is loading a library, not a main executable,
and it only actually uses the members "buf", "file" and "filename" of the
linux_binprm struct. Instead, call kernel_read() directly.
Link: http://lkml.kernel.org/r/20190524201817.16509-1-jannh@google.com
Fixes: 287980e49ffc ("remove lots of IS_ERR_VALUE abuses")
Signed-off-by: Jann Horn <jannh@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ever since the initial commit of the binfmt_flat shared library support back in the bitkeeper days we've offset the actual in-memory .data start by one field per possible shared library, or 1 in case shared library support isn't enabled. I can't find anything in the loader that actually makes use of it, nor was it present before shared library support it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>