rtld: Check __libc_enable_secure before honoring LD_PREFER_MAP_32BIT_EXEC (CVE-2019-19126) [BZ #25204]
The problem was introduced in glibc 2.23, in commit b9eb92ab05204df772eb4929eccd018637c9f3e9
("Add Prefer_MAP_32BIT_EXEC to map executable pages with MAP_32BIT").
H.J. Lu [Fri, 19 Jan 2018 17:53:50 +0000 (09:53 -0800)]
x86-64: Properly align La_x86_64_retval to VEC_SIZE [BZ #22715]
_dl_runtime_profile calls _dl_call_pltexit, passing a pointer to
La_x86_64_retval which is allocated on stack. The lrv_vector0
field in La_x86_64_retval must be aligned to size of vector register.
When allocating stack space for La_x86_64_retval, we need to make sure
that the address of La_x86_64_retval + RV_VECTOR0_OFFSET is aligned to
VEC_SIZE. This patch checks the alignment of the lrv_vector0 field
and pads the stack space if needed.
Tested with x32 and x86-64 on SSE4, AVX and AVX512 machines. It fixed
Florian Weimer [Thu, 11 Jan 2018 15:54:40 +0000 (16:54 +0100)]
x86: Fix mis-merge of XSAVE ld.so trampoline selection [BZ #22641]
The change is best viewed with “diff -w”:
@@ -226,6 +226,7 @@ init_cpu_features (struct cpu_features *cpu_features)
/* Determine if FMA4 is usable. */
if (HAS_CPU_FEATURE (FMA4))
cpu_features->feature[index_FMA4_Usable] |= bit_FMA4_Usable;
+ }
/* For _dl_runtime_resolve, set xsave_state_size to xsave area
size + integer register save size and align it to 64 bytes. */
@@ -292,7 +293,6 @@ init_cpu_features (struct cpu_features *cpu_features)
}
}
}
- }
#if !HAS_CPUID
no_cpuid:
Without this change, XSAVE support will never be selected unless the CPU
also supports AVX, which is not what we want. For example, if AVX is
disabled, but MPX is supported, the BND registers are not preserved if
we use FXSAVE instead of XSAVE.
H.J. Lu [Sun, 22 Oct 2017 15:47:03 +0000 (08:47 -0700)]
x86-64: Use fxsave/xsave/xsavec in _dl_runtime_resolve [BZ #21265]
In _dl_runtime_resolve, use fxsave/xsave/xsavec to preserve all vector,
mask and bound registers. It simplifies _dl_runtime_resolve and supports
different calling conventions. ld.so code size is reduced by more than
1 KB. However, use fxsave/xsave/xsavec takes a little bit more cycles
than saving and restoring vector and bound registers individually.
Latency for _dl_runtime_resolve to lookup the function, foo, from one
shared library plus libc.so:
This is the worst case where portion of time spent for saving and
restoring registers is bigger than majority of cases. With smaller
_dl_runtime_resolve code size, overall performance impact is negligible.
On IvyBridge, differences in build and test time of binutils with lazy
binding GCC and binutils are noises. On Westmere, differences in
bootstrap and "makc check" time of GCC 7 with lazy binding GCC and
binutils are also noises.
[BZ #21265]
* sysdeps/x86/cpu-features-offsets.sym (XSAVE_STATE_SIZE_OFFSET):
New.
* sysdeps/x86/cpu-features.c: Include <libc-internal.h>.
(init_cpu_features): Set xsave_state_size and bit_XSAVEC_Usable
if needed.
* sysdeps/x86/cpu-features.h (bit_XSAVEC_Usable): New.
(STATE_SAVE_OFFSET): Likewise.
(STATE_SAVE_MASK): Likewise.
[__ASSEMBLER__]: Include <cpu-features-offsets.h>.
(cpu_features): Add xsave_state_size.
(index_XSAVEC_Usable): New.
* sysdeps/x86_64/dl-machine.h (elf_machine_runtime_setup):
Replace _dl_runtime_resolve_sse, _dl_runtime_resolve_avx and
_dl_runtime_resolve_avx512 with _dl_runtime_resolve_fxsave,
_dl_runtime_resolve_xsave and _dl_runtime_resolve_xsavec.
* sysdeps/x86_64/dl-trampoline.S: Include <cpu-features.h>.
(DL_RUNTIME_UNALIGNED_VEC_SIZE): Removed.
(DL_RUNTIME_RESOLVE_REALIGN_STACK): Check STATE_SAVE_ALIGNMENT
instead of VEC_SIZE.
(REGISTER_SAVE_BND0): Removed.
(REGISTER_SAVE_BND1): Likewise.
(REGISTER_SAVE_BND3): Likewise.
(REGISTER_SAVE_RAX): Always defined to 0.
(VMOV): Removed.
(_dl_runtime_resolve_avx512): Likewise.
(_dl_runtime_resolve_avx): Likewise.
(_dl_runtime_resolve_sse): Likewise.
(USE_FXSAVE): New.
(_dl_runtime_resolve_fxsave): Likewise.
(USE_XSAVE): Likewise.
(_dl_runtime_resolve_xsave): Likewise.
(USE_XSAVEC): Likewise.
(_dl_runtime_resolve_xsavec): Likewise.
* sysdeps/x86_64/dl-trampoline.h (_dl_runtime_resolve_avx512):
Removed.
(_dl_runtime_resolve_avx): Likewise.
(_dl_runtime_resolve_sse): Likewise.
(_dl_runtime_resolve_fxsave): New.
(_dl_runtime_resolve_xsave): Likewise.
(_dl_runtime_resolve_xsavec): Likewise.
(_dl_runtime_profile): Defined only if _dl_runtime_profile is
defined.
H.J. Lu [Thu, 19 Oct 2017 15:55:56 +0000 (08:55 -0700)]
x86-64: Verify that _dl_runtime_resolve preserves vector registers
On x86-64, _dl_runtime_resolve must preserve the first 8 vector
registers. Add 3 _dl_runtime_resolve tests to verify that SSE,
AVX and AVX512 registers are preserved.
Florian Weimer [Wed, 14 Jun 2017 06:11:22 +0000 (08:11 +0200)]
i686: Add missing IS_IN (libc) guards to vectorized strcspn
Since commit d957c4d3fa48d685ff2726c605c988127ef99395 (i386: Compile
rtld-*.os with -mno-sse -mno-mmx -mfpmath=387), vector intrinsics can
no longer be used in ld.so, even if the compiled code never makes it
into the final ld.so link. This commit adds the missing IS_IN (libc)
guard to the SSE 4.2 strcspn implementation, so that it can be used from
ld.so in the future.
Ignore and remove LD_HWCAP_MASK for AT_SECURE programs (bug #21209)
The LD_HWCAP_MASK environment variable may alter the selection of
function variants for some architectures. For AT_SECURE process it
means that if an outdated routine has a bug that would otherwise not
affect newer platforms by default, LD_HWCAP_MASK will allow that bug
to be exploited.
To be on the safe side, ignore and disable LD_HWCAP_MASK for setuid
binaries.
Drop the GLIBC_TUNABLES environment variable from the environment of
setxid processes to avoid passing it on to non-setxid children. This
prevents potentially insecure tunables in the GLIBC_TUNABLES envvar
from crossing over into a child that may use a libc that has tunables
support.
powerpc: Fix write-after-destroy in lock elision [BZ #20822]
The update of *adapt_count after the release of the lock causes a race
condition when thread A unlocks, thread B continues and destroys the
mutex, and thread A writes to *adapt_count.
Mike Frysinger [Thu, 15 Dec 2016 23:34:05 +0000 (18:34 -0500)]
localedata: bs_BA: fix yesexpr/noexpr [BZ #20974]
Both regexes end with a "*." which means the previous match can be
omitted, and then the . allows them to match any input at all.
This means tools like coreutils' `rm -i` will always delete things
when prompted because the yesexpr regex matches all inputs (even
the negative ones).
Aurelien Jarno [Tue, 2 Aug 2016 07:18:59 +0000 (09:18 +0200)]
alpha: fix trunc for big input values
The alpha specific version of trunc and truncf always add and subtract
0x1.0p23 or 0x1.0p52 even for big values. This causes this kind of
errors in the testsuite:
Change this by returning the input value when its absolute value is
greater than 0x1.0p23 or 0x1.0p52. NaN have to go through the add and
subtract operations to get possibly silenced.
Finally remove the code to handle inexact exception, trunc should never
generate such an exception.
Changelog:
* sysdeps/alpha/fpu/s_trunc.c (__trunc): Return the input value
when its absolute value is greater than 0x1.0p52.
[_IEEE_FP_INEXACT] Remove.
* sysdeps/alpha/fpu/s_truncf.c (__truncf): Return the input value
when its absolute value is greater than 0x1.0p23.
[_IEEE_FP_INEXACT] Remove.
Aurelien Jarno [Tue, 2 Aug 2016 07:18:59 +0000 (09:18 +0200)]
alpha: fix rint on sNaN input
The alpha version of rint wrongly return sNaN for sNaN input. Fix that
by checking for NaN and by returning the input value added with itself
in that case.
Changelog:
* sysdeps/alpha/fpu/s_rint.c (__rint): Add argument with itself
when it is a NaN.
* sysdeps/alpha/fpu/s_rintf.c (__rintf): Likewise.
Aurelien Jarno [Tue, 2 Aug 2016 07:18:59 +0000 (09:18 +0200)]
alpha: fix floor on sNaN input
The alpha version of floor wrongly return sNaN for sNaN input. Fix that
by checking for NaN and by returning the input value added with itself
in that case.
Finally remove the code to handle inexact exception, floor should never
generate such an exception.
Changelog:
* sysdeps/alpha/fpu/s_floor.c (__floor): Add argument with itself
when it is a NaN.
[_IEEE_FP_INEXACT] Remove.
* sysdeps/alpha/fpu/s_floorf.c (__floorf): Likewise.
Aurelien Jarno [Tue, 2 Aug 2016 07:18:59 +0000 (09:18 +0200)]
alpha: fix ceil on sNaN input
The alpha version of ceil wrongly return sNaN for sNaN input. Fix that
by checking for NaN and by returning the input value added with itself
in that case.
Finally remove the code to handle inexact exception, ceil should never
generate such an exception.
Changelog:
* sysdeps/alpha/fpu/s_ceil.c (__ceil): Add argument with itself
when it is a NaN.
[_IEEE_FP_INEXACT] Remove.
* sysdeps/alpha/fpu/s_ceilf.c (__ceilf): Likewise.
MIPS: Add `.insn' to ensure a text label is defined as code not data
Avoid a build error with microMIPS compilation and recent versions of
GAS which complain if a branch targets a label which is marked as data
rather than microMIPS code:
../sysdeps/mips/mips32/crti.S: Assembler messages:
../sysdeps/mips/mips32/crti.S:72: Error: branch to a symbol in another ISA mode
make[2]: *** [.../csu/crti.o] Error 1
as commit 9d862524f6ae ("MIPS: Verify the ISA mode and alignment of
branch and jump targets") closed a hole in branch processing, making
relocation calculation respect the ISA mode of the symbol referred.
This allowed diagnosing the situation where an attempt is made to pass
control from code assembled for one ISA mode to code assembled for a
different ISA mode and either relaxing the branch to a cross-mode jump
or if that is not possible, then reporting this as an error rather than
letting such code build and then fail unpredictably at the run time.
This however requires the correct annotation of branch targets as code,
because the ISA mode is not relevant for data symbols and is therefore
not recorded for them. The `.insn' pseudo-op is used for this purpose
and has been supported by GAS since:
Wed Feb 12 14:36:29 1997 Ian Lance Taylor <ian@cygnus.com>
so there has been no reason to avoid it where required. More recently
this pseudo-op has been documented, by the microMIPS architecture
specification[1][2], as required for the correct interpretation of any
code label which is not followed by an actual instruction in an assembly
source.
Use it in our crti.S files then, to mark that the trailing label there
with no instructions following is indeed not a code bug and the branch
is legitimate.
References:
[1] "MIPS Architecture for Programmers, Volume II-B: The microMIPS32
Instruction Set", MIPS Technologies, Inc., Document Number: MD00582,
Revision 5.04, January 15, 2014, Section 7.1 "Assembly-Level
Compatibility", p. 533
[2] "MIPS Architecture for Programmers, Volume II-B: The microMIPS64
Instruction Set", MIPS Technologies, Inc., Document Number: MD00594,
Revision 5.04, January 15, 2014, Section 8.1 "Assembly-Level
Compatibility", p. 623
2016-11-23 Matthew Fortune <Matthew.Fortune@imgtec.com>
Maciej W. Rozycki <macro@imgtec.com>
Denis Kaganovich [Thu, 20 Oct 2016 20:01:39 +0000 (22:01 +0200)]
configure: accept __stack_chk_fail_local for ssp support too [BZ #20662]
When glibc is compiled with gcc 6.2 that has been configured with
--enable-default-pie and --enable-default-ssp, the configure script
fails to detect that the compiler has ssp turned on by default when
being built for i686-linux-gnu.
This is because gcc is emitting __stack_chk_fail_local but the
script is only looking for __stack_chk_fail. Support both.
Example output:
checking whether x86_64-pc-linux-gnu-gcc -m32 -Wl,-O1 -Wl,--as-needed
implicitly enables -fstack-protector... no
Fix cos computation for multiple precision fallback (bz #20357)
During the sincos consolidation I made two mistakes, one was a logical
error due to which cos(0x1.8475e5afd4481p+0) returned
sin(0x1.8475e5afd4481p+0) instead.
The second issue was an error in negating inputs for the correct
quadrants for sine. I could not find a suitable test case for this
despite running a program to search for such an input for a couple of
hours.
Following patch fixes both issues. Tested on x86_64. Thanks to Matt
Clay for identifying the issue.
[BZ #20357]
* sysdeps/ieee754/dbl-64/s_sin.c (sloww): Fix up condition
to call __mpsin/__mpcos and to negate values.
* math/auto-libm-test-in: Add test.
* math/auto-libm-test-out: Regenerate.
Andrew Senkevich [Mon, 17 Oct 2016 14:55:28 +0000 (17:55 +0300)]
Fixed x86_64 vector sincos/sincosf ABI.
Fixed wrong vector sincos/sincosf ABI to have it compatible with
current vector function declaration "#pragma omp declare simd notinbranch",
according to which vector sincos should have vector of pointers for second and
third parameters. It is fixed with implementation as wrapper to version
having second and third parameters as pointers.
Florian Weimer [Thu, 18 Aug 2016 09:15:42 +0000 (11:15 +0200)]
argp: Do not override GCC keywords with macros [BZ #16907]
glibc provides fallback definitions already. It is not necessary to
suppress warnings for unknown attributes because GCC does this
automatically for system headers.
This commit does not sync with gnulib because gnulib has started to use
_GL_* macros in the header file, which are arguably in the gnulib
implementation space and not suitable for an installed glibc header
file.
Florian Weimer [Sat, 11 Jun 2016 10:12:56 +0000 (12:12 +0200)]
nss_db: Fix initialization of iteration position [BZ #20237]
When get*ent is called without a preceding set*ent, we need
to set the initial iteration position in get*ent.
Reproducer: Add “services: db files” to /etc/nsswitch.conf, then run
“perl -e getservent”. It will segfault before this change, and exit
silently after it.
Florian Weimer [Tue, 21 Jun 2016 19:29:21 +0000 (21:29 +0200)]
malloc: Avoid premature fallback to mmap [BZ #20284]
Before this change, the while loop in reused_arena which avoids
returning a corrupt arena would never execute its body if the selected
arena were not corrupt. As a result, result == begin after the loop,
and the function returns NULL, triggering fallback to mmap.
It is necessary to preserve the invariant that if an arena is
on the free list, it has thread attach count zero. Otherwise,
when arena_thread_freeres sees the zero attach count, it will
add it, and without the invariant, an arena could get pushed
to the list twice, resulting in a cycle.
One possible execution trace looks like this:
Thread 1 examines free list and observes it as empty.
Thread 2 exits and adds its arena to the free list,
with attached_threads == 0).
Thread 1 selects this arena in reused_arena (not from the free list).
Thread 1 increments attached_threads and attaches itself.
(The arena remains on the free list.)
Thread 1 exits, decrements attached_threads,
and adds the arena to the free list.
The final step creates a cycle in the usual way (by overwriting the
next_free member with the former list head, while there is another
list item pointing to the arena structure).
tst-malloc-thread-exit exhibits this issue, but it was only visible
with a debugger because the incorrect fix in bug 19243 removed
the assert from get_free_list.
Florian Weimer [Thu, 4 Aug 2016 09:10:57 +0000 (11:10 +0200)]
x86: Use sysdep.o from libc.a in static libraries
Static libraries can use the sysdep.o copy in libc.a without
a performance penalty. This results in a visible difference
if libpthread.a is relinked into a single object file (which
is needed to support libraries which check for the presence
of certain symbols to enable threading support, which generally
fails with static linking unless libpthread.a is relinked).
Aurelien Jarno [Thu, 30 Jun 2016 14:06:10 +0000 (16:06 +0200)]
SPARC64: update localplt.data
Commits d81f90cc and 89faa0340 replaced called to __isnan and __isinf
by the corresponding GCC builtins. In turns GCC emits calls to _Qp_cmp.
We should therefore add _Qp_cmp to localplt.data as otherwise the
elf/check-localplt test fails with:
Extra PLT reference: libc.so: _Qp_cmp
A similar change has already been done for SPARC32 in commit 6ef1cb95.
Stefan Liebler [Tue, 17 May 2016 08:45:48 +0000 (10:45 +0200)]
Fix tst-cancel17/tst-cancelx17, which sometimes segfaults while exiting.
The testcase tst-cancel[x]17 ends sometimes with a segmentation fault.
This happens in one of 10000 cases. Then the real testcase has already
exited with success and returned from do_test(). The segmentation fault
occurs after returning from main in _dl_fini().
In those cases, the aio_read(&a) was not canceled because the read
request was already in progress. In the meanwhile aio_write(ap) wrote
something to the pipe and the read request is able to read the
requested byte.
The read request hasn't finished before returning from do_test().
After it finishes, it writes the return value and error code from the
read syscall to the struct aiocb a, which lies on the stack of do_test.
The stack of the subsequent function call of _dl_fini or _dl_sort_fini,
which is inlined in _dl_fini is corrupted.
In case of S390, it reads a zero and decrements it by 1:
unsigned int k = nmaps - 1;
struct link_map **runp = maps[k]->l_initfini;
The load from unmapped memory leads to the segmentation fault.
The stack corruption also happens on other architectures.
I saw them e.g. on x86 and ppc, too.
This patch adds an aio_suspend call to ensure, that the read request
is finished before returning from do_test().
ChangeLog:
* nptl/tst-cancel17.c (do_test): Wait for finishing aio_read(&a).
Aurelien Jarno [Mon, 27 Jun 2016 14:45:45 +0000 (16:45 +0200)]
MIPS: run tst-mode-switch-{1,2,3}.c using test-skeleton.c
For some reasons I have not investigated yet, tst-mode-switch-1 hangs on
a MIPS UTM-8 machine running an o32 userland and a 3.6.1 kernel.
This patch changes the test so that it runs under the test-skeleton
framework, causing the test to fail after a timeout instead of hanging
the whole testsuite. At the same time, also change the tst-mode-switch-2
and tst-mode-switch-3 tests.
Changelog:
* sysdeps/mips/tst-mode-switch-1.c (main): Converted to ...
(do_test): ... this.
(TEST_FUNCTION): New macro.
Include test-skeleton.c.
* sysdeps/mips/tst-mode-switch-2.c (main): Likewise.
* sysdeps/mips/tst-mode-switch-3.c (main): Likewise.
Aurelien Jarno [Tue, 21 Jun 2016 21:59:37 +0000 (23:59 +0200)]
MIPS, SPARC: more fixes to the vfork aliases in libpthread.so
Commit 43c29487 tried to fix the vfork aliases in libpthread.so on MIPS
and SPARC, but failed to do it correctly, introducing an ABI change.
This patch does the remaining changes needed to align the MIPS and SPARC
vfork implementations with the other architectures. That way the the
alpha version of pt-vfork.S works correctly for MIPS and SPARC. The
changes for alpha were done in 82aab97c.
Changelog:
* sysdeps/unix/sysv/linux/mips/vfork.S (__vfork): Rename into
__libc_vfork.
(__vfork) [IS_IN (libc)]: Remove alias.
(__libc_vfork) [IS_IN (libc)]: Define as an alias.
* sysdeps/unix/sysv/linux/sparc/sparc32/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/vfork.S: Likewise.
Aurelien Jarno [Sat, 18 Jun 2016 17:11:23 +0000 (19:11 +0200)]
MIPS, SPARC: fix wrong vfork aliases in libpthread.so
With recent binutils versions the GNU libc fails to build on at least
MISP and SPARC, with this kind of error:
/home/aurel32/glibc/glibc-build/nptl/libpthread.so:(*IND*+0x0): multiple definition of `vfork@GLIBC_2.0'
/home/aurel32/glibc/glibc-build/nptl/libpthread.so::(.text+0xee50): first defined here
It appears that on these architectures pt-vfork.S includes vfork.S
(through the alpha version of pt-vfork.S) and that the __vfork aliases
are not conditionalized on IS_IN (libc) like on other architectures.
Therefore the aliases are also wrongly included in libpthread.so.
Fix this by properly conditionalizing the aliases like on other
architectures.
Changelog:
* sysdeps/unix/sysv/linux/mips/vfork.S (__vfork): Conditionalize
hidden_def, weak_alias and strong_alias on [IS_IN (libc)].
* sysdeps/unix/sysv/linux/sparc/sparc32/vfork.S: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/vfork.S: Likewise.
This is due both how read and write operation update the buffer position,
taking in consideration buffer lenght instead of maximum position defined
by the open mode. This patch fixes it and also fixes fseek not returning
EINVAL for invalid whence modes.
[BZ #20012]
* libio/fmemopen.c (fmemopen_read): Use buffer maximum position, not
length to calculate the buffer to read.
(fmemopen_write): Set the buffer position based on bytes written.
(fmemopen_seek): Return EINVAL for invalid whence modes.
This is due the internal write function does not correctly update the internal
object position state and then the seek operation returns a wrong value. This
patch fixes it.
It fixes both BZ #20005 and BZ #19230 (marked as duplicated). A new test is
added to check for such case.
Florian Weimer [Mon, 7 Mar 2016 12:48:47 +0000 (13:48 +0100)]
test-skeleton.c: Do not set RLIMIT_DATA [BZ #19648]
With older kernels, it is mostly ineffective because it causes malloc
to switch from sbrk to mmap (potentially invalidating malloc testing
compared to what real appliations do). With newer kernels which
have switched to enforcing RLIMIT_DATA for mmap as well, some test
cases will fail in an unintended fashion because the limit which was
set previously does not include room for all mmap mappings.
Florian Weimer [Mon, 23 May 2016 17:43:09 +0000 (19:43 +0200)]
Make padding in struct sockaddr_storage explicit [BZ #20111]
This avoids aliasing issues with GCC 6 in -fno-strict-aliasing
mode. (With implicit padding, not all data is copied.)
This change makes it explicit that struct sockaddr_storage is
only 126 bytes large on m68k (unlike elsewhere, where we end up
with the requested 128 bytes). The new test case makes sure that
this does not happen on other architectures.
Florian Weimer [Mon, 23 May 2016 18:18:34 +0000 (20:18 +0200)]
CVE-2016-4429: sunrpc: Do not use alloca in clntudp_call [BZ #20112]
The call is technically in a loop, and under certain circumstances
(which are quite difficult to reproduce in a test case), alloca
can be invoked repeatedly during a single call to clntudp_call.
As a result, the available stack space can be exhausted (even
though individual alloca sizes are bounded implicitly by what
can fit into a UDP packet, as a side effect of the earlier
successful send operation).
Florian Weimer [Fri, 13 May 2016 14:55:01 +0000 (16:55 +0200)]
tst-mallocfork2: Fix race condition, use fewer resources
The first SIGUSR1 signal could arrive when sigusr1_sender_pid
was still 0. As a result, kill would send SIGSTOP to the
entire process group. This would cause the test to hang before
printing any output.
This commit also adds a sched_yield to the signal source, so that
it does not flood the parent process with signals it has never a
chance to handle.
Even with these changes, tst-mallocfork2 still fails reliably
after the fix in commit commit 56290d6e762c1194547e73ff0b948cd79d3a1e03
(Increase fork signal safety for single-threaded processes) is
backed out.
Florian Weimer [Thu, 12 May 2016 06:54:17 +0000 (08:54 +0200)]
Increase fork signal safety for single-threaded processes [BZ #19703]
This provides a band-aid and addresses the scenario where fork is
called from a signal handler while the process is in the malloc
subsystem (or has acquired the libio list lock). It does not
address the general issue of async-signal-safety of fork;
multi-threaded processes are not covered, and some glibc
subsystems have fork handlers which are not async-signal-safe.
Stefan Liebler [Thu, 14 Apr 2016 10:21:53 +0000 (12:21 +0200)]
Fix strfmon_l: Use specified locale for number formatting [BZ #19633]
The commit 985fc132f23dbb83de76c5af9e783ef1b5900148
"strfmon_l: Use specified locale for number formatting [BZ #19633]"
introduced an elf/check-abi-libc testfailure due to __printf_fp_l
on architectures which use sysdeps/ieee754/ldbl-opt/math_ldbl_opt.h.
This patch uses libc_hidden_def instead of ldbl_hidden_def.
The ldbl_strong_alias is removed due to the rename of ___printf_fp_l
to __printf_fp_l.
ChangeLog:
* stdio-common/printf_fp.c (__printf_fp_l):
Rename ___printf_fp_l to __printf_fp_l and
remove strong alias. Use libc_hidden_def instead
of ldbl_hidden_def macro.
CVE-2016-3706: getaddrinfo: stack overflow in hostent conversion [BZ #20010]
When converting a struct hostent response to struct gaih_addrtuple, the
gethosts macro (which is called from gaih_inet) used alloca, without
malloc fallback for large responses. This commit changes this code to
use calloc unconditionally.
This commit also consolidated a second hostent-to-gaih_addrtuple
conversion loop (in gaih_inet) to use the new conversion function.
Florian Weimer [Thu, 31 Mar 2016 09:26:55 +0000 (11:26 +0200)]
Report dlsym, dlvsym lookup errors using dlerror [BZ #19509]
* elf/dl-lookup.c (_dl_lookup_symbol_x): Report error even if
skip_map != NULL.
* elf/tst-dlsym-error.c: New file.
* elf/Makefile (tests): Add tst-dlsym-error.
(tst-dlsym-error): Link against libdl.
Florian Weimer [Wed, 4 May 2016 10:09:35 +0000 (12:09 +0200)]
CVE-2016-1234: glob: Do not copy d_name field of struct dirent [BZ #19779]
Instead, we store the data we need from the return value of
readdir in an object of the new type struct readdir_result.
This type is independent of the layout of struct dirent.
glob: Simplify the interface for the GLOB_ALTDIRFUNC callback gl_readdir
Previously, application code had to set up the d_namlen member if
the target supported it, involving conditional compilation. After
this change, glob will use the length of the string in d_name instead
of d_namlen to determine the file name length. All glibc targets
provide the d_type and d_ino members, and setting them as needed for
gl_readdir is straightforward.
Changing the behavior with regards to d_ino is left to a future
cleanup.
resolv: Always set *resplen2 out parameter in send_vc [BZ #19825]
In various error scenarios (for example, if the server closes the
TCP connection before sending the full response), send_vc can return
without resetting the *resplen2 value. This can pass uninitialized
or unexpected data to the caller.
nss_dns: Check address length before creating addrinfo result [BZ #19831]
Previously, we allocated room in the result space before the check,
leaving uninitialized data there in case the check failed.
This also consolidates the behavior between single (A or AAAA) and
dual (A and AAAA in parallel) queries. Single queries checked
the record length against the QTYPE, not the RRTYPE.
The fork handler now runs so late that there is no risk anymore that
other fork handlers in the same thread use malloc, so it is no
longer necessary to install malloc hooks which made a subset
of malloc functionality available to the thread that called fork.
Samuel Thibault [Tue, 22 Mar 2016 08:58:48 +0000 (09:58 +0100)]
Fix malloc threaded tests link on non-Linux
* malloc/Makefile ($(objpfx)tst-malloc-backtrace,
$(objpfx)tst-malloc-thread-exit, $(objpfx)tst-malloc-thread-fail): Use
$(shared-thread-library) instead of hardcoding the path to libpthread.
Florian Weimer [Mon, 2 May 2016 13:25:20 +0000 (15:25 +0200)]
hesiod: Always use thread-local resolver state [BZ #19573]
The Hesiod implementation imported into glibc was enhanced
to support caller-supplied resolver states. But its only
consumer is nss_hesiod, and it supplies the thread-local
resolver state. Therefore, this commit changes the Hesiod
implementation to use the thread-local resolver state (_res)
directly. This fixes bug 19573 because the Hesiod
implementation no longer has to initialize and free any
resolver state.
To avoid any risk of interposition of ABI-incompatible Hesiod
function implementations, this commit marks the Hesiod functions
as hidden. (They were already hidden using a linker version
script.)
Florian Weimer [Wed, 4 May 2016 12:45:17 +0000 (14:45 +0200)]
getnameinfo: Return EAI_OVERFLOW in more cases [BZ #19787]
The AF_LOCAL and AF_INET/AF_INET6 non-numerci service conversion
did not return EAI_OVERFLOW if the supplied buffer was too small,
silently returning truncated data. In the AF_INET/AF_INET6
numeric cases, the snprintf return value checking was incorrect.
Florian Weimer [Wed, 4 May 2016 12:35:23 +0000 (14:35 +0200)]
getnameinfo: Avoid calling strnlen on uninitialized buffer
In the numeric AF_INET/AF_INET6 case, if inet_ntop fails
as the result of a short host buffer, we used to call strnlen
on the uninitialized host buffer.
Florian Weimer [Tue, 29 Mar 2016 09:27:32 +0000 (11:27 +0200)]
nss_db: Propagate ERANGE error if parse_line fails [BZ #19837]
Reproducer (needs to run as root):
perl -e \
'print "large:x:999:" . join(",", map {"user$_"} (1 .. 135))."\n"' \
>> /etc/group
cd /var/db
make
getent -s db group
After the fix, the last command should list the "large" group.
The magic number 135 has been chosen so that the line is shorter than
1024 bytes, but the pointers required to encode the member array will
cross the threshold, triggering the bug.
Stefan Liebler [Fri, 1 Apr 2016 12:11:10 +0000 (14:11 +0200)]
S390: Extend structs La_s390_regs / La_s390_retval with vector-registers.
Starting with z13, vector registers can also occur as argument registers.
Thus the passed input/output register structs for
la_s390_[32|64]_gnu_plt[enter|exit] functions should reflect those new
registers. This patch extends these structs La_s390_regs and La_s390_retval
and adjusts _dl_runtime_profile() to handle those fields in case of
running on a z13 machine.
Stefan Liebler [Fri, 1 Apr 2016 12:11:10 +0000 (14:11 +0200)]
S390: Save and restore fprs/vrs while resolving symbols.
On s390, no fpr/vrs were saved while resolving a symbol
via _dl_runtime_resolve/_dl_runtime_profile.
According to the abi, the fpr-arguments are defined as call clobbered.
In leaf-functions, gcc 4.9 and newer can use fprs for saving/restoring gprs
instead of saving them to the stack.
If gcc do this in one of the resolver-functions, then the floating point
arguments of a library-function are invalid for the first library-function-call.
Thus, this patch saves/restores the fprs around the resolving code.
The same could occur for vector registers. Furthermore an ifunc-resolver
could also clobber the vector/floating point argument registers.
Thus this patch provides the further variants _dl_runtime_resolve_vx/
_dl_runtime_profile_vx, which are used if the kernel claims, that
we run on a machine with vector registers.
Furthermore, if _dl_runtime_profile calls _dl_call_pltexit,
the pointers to inregs-/outregs-structs were setup invalid.
Now they point to the correct location in the stack-frame.
Before branching back to the caller, the return values are now
restored instead of containing the return values of the
_dl_call_pltexit() call.
On s390-32, an endless loop occurs if _dl_call_pltexit() should be called.
Now, this code-path branches to this function instead of just after the
preceding basr-instruction.
* sysdeps/s390/s390-32/dl-trampoline.S: Include dl-trampoline.h twice
to create a non-vector/vector version for _dl_runtime_resolve and
_dl_runtime_profile. Move implementation to ...
* sysdeps/s390/s390-32/dl-trampoline.h: ... here.
(_dl_runtime_resolve) Save and restore fpr/vrs.
(_dl_runtime_profile) Save and restore vrs and fix some issues
if _dl_call_pltexit is called.
* sysdeps/s390/s390-32/dl-machine.h (elf_machine_runtime_setup):
Choose the correct resolver function if running on a machine with vx.
* sysdeps/s390/s390-64/dl-trampoline.S: Include dl-trampoline.h twice
to create a non-vector/vector version for _dl_runtime_resolve and
_dl_runtime_profile. Move implementation to ...
* sysdeps/s390/s390-64/dl-trampoline.h: ... here.
(_dl_runtime_resolve) Save and restore fpr/vrs.
(_dl_runtime_profile) Save and restore vrs and fix some issues
* sysdeps/s390/s390-64/dl-machine.h: (elf_machine_runtime_setup):
Choose the correct resolver function if running on a machine with vx.
Florian Weimer [Fri, 25 Mar 2016 10:49:51 +0000 (11:49 +0100)]
resolv: Always set *resplen2 out parameter in send_dg [BZ #19791]
Since commit 44d20bca52ace85850012b0ead37b360e3ecd96e (Implement
second fallback mode for DNS requests), there is a code path which
returns early, before *resplen2 is initialized. This happens if the
name server address is immediately recognized as invalid (because of
lack of protocol support, or if it is a broadcast address such
255.255.255.255, or another invalid address).
If this happens and *resplen2 was non-zero (which is the case if a
previous query resulted in a failure), __libc_res_nquery would reuse
an existing second answer buffer. This answer has been previously
identified as unusable (for example, it could be an NXDOMAIN
response). Due to the presence of a second answer, no name server
switching will occur. The result is a name resolution failure,
although a successful resolution would have been possible if name
servers have been switched and queries had proceeded along the search
path.
The above paragraph still simplifies the situation. Before glibc
2.23, if the second answer needed malloc, the stub resolver would
still attempt to reuse the second answer, but this is not possible
because __libc_res_nsearch has freed it, after the unsuccessful call
to __libc_res_nquerydomain, and set the buffer pointer to NULL. This
eventually leads to an assertion failure in __libc_res_nquery:
/* Make sure both hp and hp2 are defined */
assert((hp != NULL) && (hp2 != NULL));
If assertions are disabled, the consequence is a NULL pointer
dereference on the next line.
Starting with glibc 2.23, as a result of commit e9db92d3acfe1822d56d11abcea5bfc4c41cf6ca (CVE-2015-7547: getaddrinfo()
stack-based buffer overflow (Bug 18665)), the second answer is always
allocated with malloc. This means that the assertion failure happens
with small responses as well because there is no buffer to reuse, as
soon as there is a name resolution failure which triggers a search for
an answer along the search path.
This commit addresses the issue by ensuring that *resplen2 is
initialized before the send_dg function returns.
This commit also addresses a bug where an invalid second reply is
incorrectly returned as a valid to the caller.
Dylan Alex Simon [Tue, 15 Mar 2016 17:20:01 +0000 (13:20 -0400)]
math: don't clobber old libm.so on install [BZ #19822]
When installing glibc (w/mathvec enabled) in-place on a system with
a glibc w/out mathvec enabled, the install will clobber the existing
libm.so (e.g., /lib64/libm-2.21.so) with a linker script. This is
because libm.so is a symlink to libm.so.6 which is a symlink to the
final libm-2.21.so file. When the makefile writes the linker script
directly to libm.so, it gets clobbered.
The simple patch below to math/Makefile fixes this. It is based on
the nptl Makefile, which does exactly the same thing in a safer way.
Andreas Schwab [Wed, 18 Nov 2015 14:45:59 +0000 (15:45 +0100)]
Fix resource leak in resolver (bug 19257)
The number of currently defined nameservers is stored in ->nscount,
whereas ->_u._ext.nscount is set by __libc_res_nsend only after local
initializations.
Aurelien Jarno [Tue, 8 Mar 2016 23:25:00 +0000 (00:25 +0100)]
mips: terminate the FDE before the return trampoline in makecontext
In makecontext the FDE needs to be terminated before the return
trampoline otherwise backtrace called within a context created by
makecontext yields infinite backtrace.
This bug has been present for a long time, stdlib/tst-makecontext did
not fail until recent commit e535ce25. Tested on mips-linux-gnu and
mips64el-linux-gnuabi64 and mips-linux-gnu, no regression.