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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
mksysmap 
#!/bin/sh -x
# Based on the vmlinux file create the System.map file
# System.map is used by module-init tools and some debugging
# tools to retrieve the actual addresses of symbols in the kernel.
#
# Usage
# mksysmap vmlinux System.map


#####
# Generate System.map (actual filename passed as second argument)

# $NM produces the following output:
# f0081e80 T alloc_vfsmnt

#   The second row specify the type of the symbol:
#   A = Absolute
#   B = Uninitialised data (.bss)
#   C = Common symbol
#   D = Initialised data
#   G = Initialised data for small objects
#   I = Indirect reference to another symbol
#   N = Debugging symbol
#   R = Read only
#   S = Uninitialised data for small objects
#   T = Text code symbol
#   U = Undefined symbol
#   V = Weak symbol
#   W = Weak symbol
#   Corresponding small letters are local symbols

# For System.map filter away:
#   a - local absolute symbols
#   U - undefined global symbols
#   N - debugging symbols
#   w - local weak symbols

# readprofile starts reading symbols when _stext is found, and
# continue until it finds a symbol which is not either of 'T', 't',
# 'W' or 'w'. __crc_ are 'A' and placed in the middle
# so we just ignore them to let readprofile continue to work.
# (At least sparc64 has __crc_ in the middle).

$NM -n $1 | grep -v '\( [aNUw] \)\|\(__crc_\)\|\( \$[adt]\)\|\( .L\)' > $2
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