[3.7] closes bpo-39510: Fix use-after-free in BufferedReader.readinto() (GH-18295)#18349
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…thonGH-18295) When called on a closed object, readinto() segfaults on account of a write to a freed buffer: ==220553== Process terminating with default action of signal 11 (SIGSEGV): dumping core ==220553== Access not within mapped region at address 0x2A ==220553== at 0x48408A0: memmove (vg_replace_strmem.c:1272) ==220553== by 0x58DB0C: _buffered_readinto_generic (bufferedio.c:972) ==220553== by 0x58DCBA: _io__Buffered_readinto_impl (bufferedio.c:1053) ==220553== by 0x58DCBA: _io__Buffered_readinto (bufferedio.c.h:253) Reproducer: reader = open ("/dev/zero", "rb") _void = reader.read (42) reader.close () reader.readinto (bytearray (42)) GH-GH-GH- BANG! The problem exists since 2012 when commit dc46945 added code to free the read buffer on close(). Signed-off-by: Philipp Gesang <philipp.gesang@intra2net.com> (cherry picked from commit cb1c074) Co-authored-by: Philipp Gesang <phg@phi-gamma.net>
benjaminp
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Feb 4, 2020
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@phi-gamma and @benjaminp: Status check is done, and it's a success ✅ . |
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@phi-gamma and @benjaminp: Status check is done, and it's a success ✅ . |
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When called on a closed object, readinto() segfaults on account
of a write to a freed buffer:
Reproducer:
The problem exists since 2012 when commit dc46945 added code
to free the read buffer on close().
Signed-off-by: Philipp Gesang philipp.gesang@intra2net.com
(cherry picked from commit cb1c074)
Co-authored-by: Philipp Gesang phg@phi-gamma.net
https://bugs.python.org/issue39510