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  1. 22 Sep, 2016 7 commits
  3. 21 Sep, 2016 1 commit
  5. 20 Sep, 2016 5 commits
    • Al Viro's avatar
      fix fault_in_multipages_...() on architectures with no-op access_ok() · e23d4159
      Al Viro authored 
      Switching iov_iter fault-in to multipages variants has exposed an old
bug in underlying fault_in_multipages_...(); they break if the range
passed to them wraps around.  Normally access_ok() done by callers will
prevent such (and it's a guaranteed EFAULT - ERR_PTR() values fall into
such a range and they should not point to any valid objects).

However, on architectures where userland and kernel live in different
MMU contexts (e.g. s390) access_ok() is a no-op and on those a range
with a wraparound can reach fault_in_multipages_...().

Since any wraparound means EFAULT there, the fix is trivial - turn
those

    while (uaddr <= end)
	    ...
into

    if (unlikely(uaddr > end))
	    return -EFAULT;
    do
	    ...
    while (uaddr <= end);
Reported-by: default avatarJan Stancek <jstancek@redhat.com>
Tested-by: default avatarJan Stancek <jstancek@redhat.com>
Cc: stable@vger.kernel.org # v3.5+
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e23d4159
    • Laura Abbott's avatar
      mm: usercopy: Check for module addresses · aa4f0601
      Laura Abbott authored 
      While running a compile on arm64, I hit a memory exposure

usercopy: kernel memory exposure attempt detected from fffffc0000f3b1a8 (buffer_head) (1 bytes)
------------[ cut here ]------------
kernel BUG at mm/usercopy.c:75!
Internal error: Oops - BUG: 0 [#1] SMP
Modules linked in: ip6t_rpfilter ip6t_REJECT
nf_reject_ipv6 xt_conntrack ip_set nfnetlink ebtable_broute bridge stp
llc ebtable_nat ip6table_security ip6table_raw ip6table_nat
nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle
iptable_security iptable_raw iptable_nat nf_conntrack_ipv4
nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle
ebtable_filter ebtables ip6table_filter ip6_tables vfat fat xgene_edac
xgene_enet edac_core i2c_xgene_slimpro i2c_core at803x realtek xgene_dma
mdio_xgene gpio_dwapb gpio_xgene_sb xgene_rng mailbox_xgene_slimpro nfsd
auth_rpcgss nfs_acl lockd grace sunrpc xfs libcrc32c sdhci_of_arasan
sdhci_pltfm sdhci mmc_core xhci_plat_hcd gpio_keys
CPU: 0 PID: 19744 Comm: updatedb Tainted: G        W 4.8.0-rc3-threadinfo+ #1
Hardware name: AppliedMicro X-Gene Mustang Board/X-Gene Mustang Board, BIOS 3.06.12 Aug 12 2016
task: fffffe03df944c00 task.stack: fffffe00d128c000
PC is at __check_object_size+0x70/0x3f0
LR is at __check_object_size+0x70/0x3f0
...
[<fffffc00082b4280>] __check_object_size+0x70/0x3f0
[<fffffc00082cdc30>] filldir64+0x158/0x1a0
[<fffffc0000f327e8>] __fat_readdir+0x4a0/0x558 [fat]
[<fffffc0000f328d4>] fat_readdir+0x34/0x40 [fat]
[<fffffc00082cd8f8>] iterate_dir+0x190/0x1e0
[<fffffc00082cde58>] SyS_getdents64+0x88/0x120
[<fffffc0008082c70>] el0_svc_naked+0x24/0x28

fffffc0000f3b1a8 is a module address. Modules may have compiled in
strings which could get copied to userspace. In this instance, it
looks like "." which matches with a size of 1 byte. Extend the
is_vmalloc_addr check to be is_vmalloc_or_module_addr to cover
all possible cases.
Signed-off-by: default avatarLaura Abbott <labbott@redhat.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      aa4f0601
    • Jiri Olsa's avatar
      fs/proc/kcore.c: Add bounce buffer for ktext data · df04abfd
      Jiri Olsa authored 
      We hit hardened usercopy feature check for kernel text access by reading
kcore file:

  usercopy: kernel memory exposure attempt detected from ffffffff8179a01f (<kernel text>) (4065 bytes)
  kernel BUG at mm/usercopy.c:75!

Bypassing this check for kcore by adding bounce buffer for ktext data.
Reported-by: default avatarSteve Best <sbest@redhat.com>
Fixes: f5509cc1 ("mm: Hardened usercopy")
Suggested-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      df04abfd
    • Jiri Olsa's avatar
      fs/proc/kcore.c: Make bounce buffer global for read · f5beeb18
      Jiri Olsa authored 
      Next patch adds bounce buffer for ktext area, so it's
convenient to have single bounce buffer for both
vmalloc/module and ktext cases.
Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f5beeb18
    • Jan Beulich's avatar
      locking/rwsem, x86: Drop a bogus cc clobber · c907420f
      Jan Beulich authored 
      With the addition of uses of GCC's condition code outputs in commit:

  35ccfb71 ("x86, asm: Use CC_SET()/CC_OUT() in <asm/rwsem.h>")

... there's now an overlap of outputs and clobbers in __down_write_trylock().

Such overlaps are generally getting tagged with an error (occasionally
even with an ICE). I can't really tell why plain GCC 6.2 doesn't detect
this (judging by the code it is meant to), while the slightly modified
one I use does. Since condition code clobbers are never necessary on x86
(other than perhaps for documentation purposes, which doesn't really
get done consistently), remove it altogether rather than inventing
something like CC_CLOBBER (to accompany CC_SET/CC_OUT).
Signed-off-by: default avatarJan Beulich <jbeulich@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/57E003CC0200007800110102@prv-mh.provo.novell.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      c907420f
  7. 19 Sep, 2016 27 commits
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