Noah Goldstein [Sun, 9 Jan 2022 22:02:21 +0000 (16:02 -0600)]
x86: Fix __wcsncmp_avx2 in strcmp-avx2.S [BZ# 28755]
Fixes [BZ# 28755] for wcsncmp by redirecting length >= 2^56 to
__wcscmp_avx2. For x86_64 this covers the entire address range so any
length larger could not possibly be used to bound `s1` or `s2`.
test-strcmp, test-strncmp, test-wcscmp, and test-wcsncmp all pass.
getcwd: Set errno to ERANGE for size == 1 (CVE-2021-3999)
No valid path returned by getcwd would fit into 1 byte, so reject the
size early and return NULL with errno set to ERANGE. This change is
prompted by CVE-2021-3999, which describes a single byte buffer
underflow and overflow when all of the following conditions are met:
- The buffer size (i.e. the second argument of getcwd) is 1 byte
- The current working directory is too long
- '/' is also mounted on the current working directory
Sequence of events:
- In sysdeps/unix/sysv/linux/getcwd.c, the syscall returns ENAMETOOLONG
because the linux kernel checks for name length before it checks
buffer size
- The code falls back to the generic getcwd in sysdeps/posix
- In the generic func, the buf[0] is set to '\0' on line 250
- this while loop on line 262 is bypassed:
while (!(thisdev == rootdev && thisino == rootino))
since the rootfs (/) is bind mounted onto the directory and the flow
goes on to line 449, where it puts a '/' in the byte before the
buffer.
- Finally on line 458, it moves 2 bytes (the underflowed byte and the
'\0') to the buf[0] and buf[1], resulting in a 1 byte buffer overflow.
- buf is returned on line 469 and errno is not set.
It is a wrapper for Linux clone syscall, to simplify the call to the
use only the most common arguments and remove architecture specific
handling (such as ia64 different name and signature).
realpath: Set errno to ENAMETOOLONG for result larger than PATH_MAX [BZ #28770]
realpath returns an allocated string when the result exceeds PATH_MAX,
which is unexpected when its second argument is not NULL. This results
in the second argument (resolved) being uninitialized and also results
in a memory leak since the caller expects resolved to be the same as the
returned value.
Return NULL and set errno to ENAMETOOLONG if the result exceeds
PATH_MAX. This fixes [BZ #28770], which is CVE-2021-3998.
support: Add helpers to create paths longer than PATH_MAX
Add new helpers support_create_and_chdir_toolong_temp_directory and
support_chdir_toolong_temp_directory to create and descend into
directory trees longer than PATH_MAX.
Florian Weimer [Fri, 25 Jun 2021 06:02:30 +0000 (08:02 +0200)]
elf: Fix glibc-hwcaps priorities with cache flags mismatches [BZ #27046]
If lib->flags (in the cache) did not match GLRO (dl_correct_cache_id),
searching for further glibc-hwcaps entries did not happen, and it
was possible that the best glibc-hwcaps was not found. By accident,
this causes a test failure for elf/tst-glibc-hwcaps-prepend-cache
on armv7l.
This commit changes the cache lookup logic to continue searching
if (a) no match has been found, (b) a named glibc-hwcaps match
has been found(), or (c) non-glibc-hwcaps match has been found
and the entry flags and cache default flags do not match.
_DL_CACHE_DEFAULT_ID is used instead of GLRO (dl_correct_cache_id)
because the latter is only written once on i386 if loading
of libc.so.5 libraries is selected, so GLRO (dl_correct_cache_id)
should probably removed in a future change.
Paul A. Clarke [Sat, 25 Sep 2021 14:57:15 +0000 (09:57 -0500)]
powerpc: Fix unrecognized instruction errors with recent binutils
Recent versions of binutils (with commit b25f942e18d6ecd7ec3e2d2e9930eb4f996c258a) stopped preserving "sticky"
options across a base `.machine` directive, nullifying the use of
passing "-many" through GCC to the assembler. As a result, some
instructions which were recognized even under older, more stringent
`.machine` directives become unrecognized instructions in that
context.
In `sysdeps/powerpc/tst-set_ppr.c`, the use of the `mfppr32` extended
mnemonic became unrecognized, as the default compilation with GCC for
32bit powerpc adds a `.machine ppc` in the resulting assembly, so the
command line option `-Wa,-many` is essentially ignored, and the ISA 2.06
instructions and mnemonics, like `mfppr32`, are unrecognized.
The compilation of `sysdeps/powerpc/tst-set_ppr.c` fails with:
Error: unrecognized opcode: `mfppr32'
Add appropriate `.machine` directives in the assembly to bracket the
`mfppr32` instruction.
Part of a 2019 fix (commit 9250e6610fdb0f3a6f238d2813e319a41fb7a810) to
the above test's Makefile to add `-many` to the compilation when GCC
itself stopped passing `-many` to the assember no longer has any effect,
so remove that.
Florian Weimer [Tue, 9 Mar 2021 20:07:24 +0000 (21:07 +0100)]
<shlib-compat.h>: Support compat_symbol_reference for _ISOMAC
This is helpful for testing compat symbols in cases where _ISOMAC
is activated implicitly due to -DMODULE_NAME=testsuite and cannot
be disabled easily.
Aurelien Jarno [Mon, 17 Jan 2022 18:41:40 +0000 (19:41 +0100)]
x86: use default cache size if it cannot be determined [BZ #28784]
In some cases (e.g QEMU, non-Intel/AMD CPU) the cache information can
not be retrieved and the corresponding values are set to 0.
Commit 2d651eb9265d ("x86: Move x86 processor cache info to
cpu_features") changed the behaviour in such case by defining the
__x86_shared_cache_size and __x86_data_cache_size variables to 0 instead
of using the default values. This cause an issue with the i686 SSE2
optimized bzero/routine which assumes that the cache size is at least
128 bytes, and otherwise tries to zero/set the whole address space minus
128 bytes.
Fix that by restoring the original code to only update
__x86_shared_cache_size and __x86_data_cache_size variables if the
corresponding cache sizes are not zero.
Paul A. Clarke [Tue, 14 Sep 2021 18:13:33 +0000 (13:13 -0500)]
powerpc: Fix unrecognized instruction errors with recent GCC
Recent binutils commit b25f942e18d6ecd7ec3e2d2e9930eb4f996c258a
changes the behavior of `.machine` directives to override, rather
than augment, the base CPU. This can result in _reduced_ functionality
when, for example, compiling for default machine "power8", but explicitly
asking for ".machine power5", which loses Altivec instructions.
In tst-ucontext-ppc64-vscr.c, while the instructions provoking the new
error messages are bracketed by ".machine power5", which is ostensibly
Power ISA 2.03 (POWER5), the POWER5 processor did not support the
VSX subset, so these instructions are not recognized as "power5".
powerpc64[le]: Allocate extra stack frame on syscall.S
The syscall function does not allocate the extra stack frame for scv like other
assembly syscalls using DO_CALL_SCV. So after commit d120fb9941 changed the
offset that is used to save LR, syscall ended up using an invalid offset,
causing regressions on powerpc64. So make sure the extra stack frame is
allocated in syscall.S as well to make it consistent with other uses of
DO_CALL_SCV and avoid similar issues in the future.
Tested on powerpc, powerpc64, and powerpc64le (with and without scv)
Nikita Popov [Tue, 2 Nov 2021 08:21:42 +0000 (13:21 +0500)]
gconv: Do not emit spurious NUL character in ISO-2022-JP-3 (bug 28524)
Bugfix 27256 has introduced another issue:
In conversion from ISO-2022-JP-3 encoding, it is possible
to force iconv to emit extra NUL character on internal state reset.
To do this, it is sufficient to feed iconv with escape sequence
which switches active character set.
The simplified check 'data->__statep->__count != ASCII_set'
introduced by the aforementioned bugfix picks that case and
behaves as if '\0' character has been queued thus emitting it.
To eliminate this issue, these steps are taken:
* Restore original condition
'(data->__statep->__count & ~7) != ASCII_set'.
It is necessary since bits 0-2 may contain
number of buffered input characters.
* Check that queued character is not NUL.
Similar step is taken for main conversion loop.
Bundled test case follows following logic:
* Try to convert ISO-2022-JP-3 escape sequence
switching active character set
* Reset internal state by providing NULL as input buffer
* Ensure that nothing has been converted.
Matheus Castanho [Tue, 26 Oct 2021 13:44:59 +0000 (10:44 -0300)]
powerpc64[le]: Fix CFI and LR save address for asm syscalls [BZ #28532]
Syscalls based on the assembly templates are missing CFI for r31, which gets
clobbered when scv is used, and info for LR is inaccurate, placed in the wrong
LOC and not using the proper offset. LR was also being saved to the callee's
frame, while the ABI mandates it to be saved to the caller's frame. These are
fixed by this commit.
Florian Weimer [Wed, 24 Nov 2021 07:59:54 +0000 (08:59 +0100)]
nptl: Do not set signal mask on second setjmp return [BZ #28607]
__libc_signal_restore_set was in the wrong place: It also ran
when setjmp returned the second time (after pthread_exit or
pthread_cancel). This is observable with blocked pending
signals during thread exit.
Florian Weimer [Wed, 10 Nov 2021 14:21:37 +0000 (15:21 +0100)]
s390: Use long branches across object boundaries (jgh instead of jh)
Depending on the layout chosen by the linker, the 16-bit displacement
of the jh instruction is insufficient to reach the target label.
Analysis of the linker failure was carried out by Nick Clifton.
Reviewed-by: Carlos O'Donell <carlos@redhat.com> Reviewed-by: Stefan Liebler <stli@linux.ibm.com>
(cherry picked from commit 98966749f2b418825ff2ea496a0ee89fe63d2cc8)
@@ -856,6 +876,11 @@ no more namespaces available for dlmopen()"));
/* See if an error occurred during loading. */
if (__glibc_unlikely (exception.errstring != NULL))
{
+ /* Avoid keeping around a dangling reference to the libc.so link
+ map in case it has been cached in libc_map. */
+ if (!args.libc_already_loaded)
+ GL(dl_ns)[nsid].libc_map = NULL;
+
do_dlopen calls _dl_open with nsid == __LM_ID_CALLER (-2), which calls
dl_open_worker with args.nsid = nsid. dl_open_worker updates args.nsid
if it is __LM_ID_CALLER. After dl_open_worker returns, it is wrong to
use nsid.
Replace nsid with args.nsid after dl_open_worker returns. This fixes
BZ #27609.
Also note that the kernel commit 511ad531afd4090625def4d9aba1f5227bd44b8e
"s390/hwcaps: shorten HWCAP defines" has shortened the prefix of the macros
from "HWCAP_S390_" to "HWCAP_". For compatibility reasons, we do not
change the prefix in public glibc header file.
posix: Fix attribute access mode on getcwd [BZ #27476]
There is a GNU extension that allows to call getcwd(NULL, >0). It is
described in the documentation, but also directly in the unistd.h
header, just above the declaration.
Therefore the attribute access mode added in commit 06febd8c6705
is not correct. Drop it.
Fix failing nss/tst-nss-files-hosts-long with local resolver
When a local resolver like unbound is listening on the IPv4 loopback
address 127.0.0.1, the nss/tst-nss-files-hosts-long test fails. This is
due to:
- the default resolver in the absence of resolv.conf being 127.0.0.1
- the default DNS NSS database configuration in the absence of
nsswitch.conf being 'hosts: dns [!UNAVAIL=return] file'
This causes the requests for 'test4' and 'test6' to first be sent to the
local resolver, which responds with NXDOMAIN in the likely case those
records do no exist. In turn that causes the access to /etc/hosts to be
skipped, which is the purpose of that test.
Fix that by providing a simple nsswitch.conf file forcing access to
/etc/hosts for that test. I have tested that the only changed result in
the testsuite is that test.
Jiaxun Yang [Tue, 7 Sep 2021 05:31:42 +0000 (13:31 +0800)]
MIPS: Setup errno for {f,l,}xstat
{f,l,}xstat stub for MIPS is using INTERNAL_SYSCALL
to do xstat syscall for glibc ver, However it leaves
errno untouched and thus giving bad errno output.
Setup errno properly when syscall returns non-zero.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
(cherry picked from commit 66016ec8aeefd40e016d7040d966484c764b0e9c)
The shmmax expected value is tricky to check because kernel clamps it
to INT_MAX in two cases:
1. Compat symbols with IPC_64, i.e, 32-bit binaries running on 64-bit
kernels.
2. Default symbol without IPC_64 (defined as IPC_OLD within Linux) and
glibc always use IPC_64 for 32-bit ABIs (to support 64-bit time_t).
It means that 32-bit binaries running on 32-bit kernels will not see
shmmax being clamped.
And finding out whether the compat symbol is used would require checking
the underlying kernel against the current ABI. The shmall and shmmni
already provided enough coverage.
Checked on x86_64-linux-gnu and i686-linux-gnu. It should fix the
tst-sysvshm-linux failures on 32-bit kernels.
Nikita Popov [Thu, 12 Aug 2021 10:39:50 +0000 (16:09 +0530)]
librt: add test (bug 28213)
This test implements following logic:
1) Create POSIX message queue.
Register a notification with mq_notify (using NULL attributes).
Then immediately unregister the notification with mq_notify.
Helper thread in a vulnerable version of glibc
should cause NULL pointer dereference after these steps.
2) Once again, register the same notification.
Try to send a dummy message.
Test is considered successfulif the dummy message
is successfully received by the callback function.
Nikita Popov [Mon, 9 Aug 2021 14:47:34 +0000 (20:17 +0530)]
librt: fix NULL pointer dereference (bug 28213)
Helper thread frees copied attribute on NOTIFY_REMOVED message
received from the OS kernel. Unfortunately, it fails to check whether
copied attribute actually exists (data.attr != NULL). This worked
earlier because free() checks passed pointer before actually
attempting to release corresponding memory. But
__pthread_attr_destroy assumes pointer is not NULL.
So passing NULL pointer to __pthread_attr_destroy will result in
segmentation fault. This scenario is possible if
notification->sigev_notify_attributes == NULL (which means default
thread attributes should be used).
Fangrui Song [Thu, 8 Jul 2021 21:26:22 +0000 (14:26 -0700)]
x86_64: Remove unneeded static PIE check for undefined weak diagnostic
https://sourceware.org/bugzilla/show_bug.cgi?id=21782 dropped an ld
diagnostic for R_X86_64_PC32 referencing an undefined weak symbol in
-pie links. Arguably keeping the diagnostic like other ports is more
correct, since statically resolving movl foo(%rip), %eax to the
link-time zero address produces a corrupted output.
It turns out that --enable-static-pie builds do not depend on the ld
behavior. GCC generates GOT indirection for weak declarations for
-fPIE/-fPIC, so what ld does with the PC-relative relocation doesn't
really matter.
Florian Weimer [Tue, 1 Jun 2021 15:51:41 +0000 (17:51 +0200)]
Fix use of __pthread_attr_copy in mq_notify (bug 27896)
__pthread_attr_copy can fail and does not initialize the attribute
structure in that case.
If __pthread_attr_copy is never called and there is no allocated
attribute, pthread_attr_destroy should not be called, otherwise
there is a null pointer dereference in rt/tst-mqueue6.
dlfcn: Failures after dlmopen should not terminate process [BZ #15271]
Commit 9e78f6f6e7134a5f299cc8de77370218f8019237 ("Implement
_dl_catch_error, _dl_signal_error in libc.so [BZ #16628]") has the
side effect that distinct namespaces, as created by dlmopen, now have
separate implementations of the rtld exception mechanism. This means
that the call to _dl_catch_error from libdl in a secondary namespace
does not actually install an exception handler because the
thread-local variable catch_hook in the libc.so copy in the secondary
namespace is distinct from that of the base namepace. As a result, a
dlsym/dlopen/... failure in a secondary namespace terminates the process
with a dynamic linker error because it looks to the exception handler
mechanism as if no handler has been installed.
Backport notes: GLRO (dl_catch_error) is replaced with
_dl_catch_error_ptr to preserve _rtld_global_ro layout.
Nicholas Piggin [Thu, 20 May 2021 14:00:36 +0000 (11:00 -0300)]
powerpc: Fix handling of scv return error codes [BZ #27892]
When using scv for templated ASM syscalls, current code interprets any
negative return value as error, but the only valid error codes are in
the range -4095..-1 according to the ABI.
This commit also fixes 'signal.gen.test' strace test, where the issue
was first identified.
nptl_db: Support different libpthread/ld.so load orders (bug 27744)
libthread_db is loaded once GDB encounters libpthread, and at this
point, ld.so may not have been processed by GDB yet. As a result,
_rtld_global cannot be accessed by regular means from libthread_db.
To make this work until GDB can be fixed, acess _rtld_global through
a pointer stored in libpthread.
The new test does not reproduce bug 27744 with
--disable-hardcoded-path-in-tests, but is still a valid smoke test.
With --enable-hardcoded-path-in-tests, it is necessary to avoid
add-symbol-file because this can tickle a GDB bug.
Szabolcs Nagy [Tue, 2 Feb 2021 15:02:09 +0000 (15:02 +0000)]
Remove PR_TAGGED_ADDR_ENABLE from sys/prctl.h
The value of PR_TAGGED_ADDR_ENABLE was incorrect in the installed
headers and the prctl command macros were missing that are needed
for it to be useful (PR_SET_TAGGED_ADDR_CTRL). Linux headers have
the definitions since 5.4 so it's widely available, we don't need
to repeat these definitions. The remaining definitions are from
Linux 5.10.
To build glibc with --enable-memory-tagging, Linux 5.4 headers and
binutils 2.33.1 or newer is needed.
Fix SXID_ERASE behavior in setuid programs (BZ #27471)
When parse_tunables tries to erase a tunable marked as SXID_ERASE for
setuid programs, it ends up setting the envvar string iterator
incorrectly, because of which it may parse the next tunable
incorrectly. Given that currently the implementation allows malformed
and unrecognized tunables pass through, it may even allow SXID_ERASE
tunables to go through.
This change revamps the SXID_ERASE implementation so that:
- Only valid tunables are written back to the tunestr string, because
of which children of SXID programs will only inherit a clean list of
identified tunables that are not SXID_ERASE.
- Unrecognized tunables get scrubbed off from the environment and
subsequently from the child environment.
- This has the side-effect that a tunable that is not identified by
the setxid binary, will not be passed on to a non-setxid child even
if the child could have identified that tunable. This may break
applications that expect this behaviour but expecting such tunables
to cross the SXID boundary is wrong. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 2ed18c5b534d9e92fc006202a5af0df6b72e7aca)
Instead of passing GLIBC_TUNABLES via the environment, pass the
environment variable from parent to child. This allows us to test
multiple variables to ensure better coverage.
The test list currently only includes the case that's already being
tested. More tests will be added later. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 061fe3f8add46a89b7453e87eabb9c4695005ced)
tst-env-setuid: Use support_capture_subprogram_self_sgid
Use the support_capture_subprogram_self_sgid to spawn an sgid child. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit ca335281068a1ed549a75ee64f90a8310755956f)
Add a new function support_capture_subprogram_self_sgid that spawns an
sgid child of the running program with its own image and returns the
exit code of the child process. This functionality is used by at
least three tests in the testsuite at the moment, so it makes sense to
consolidate.
There is also a new function support_subprogram_wait which should
provide simple system() like functionality that does not set up file
actions. This is useful in cases where only the return code of the
spawned subprocess is interesting.
This patch also ports tst-secure-getenv to this new function. A
subsequent patch will port other tests. This also brings an important
change to tst-secure-getenv behaviour. Now instead of succeeding, the
test fails as UNSUPPORTED if it is unable to spawn a setgid child,
which is how it should have been in the first place. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit 716a3bdc41b2b4b864dc64475015ba51e35e1273)
The simplification of tunable_set interfaces took care of
signed/unsigned conversions while setting values, but comparison with
bounds ended up being incorrect; comparing TUNABLE_SIZE_T values for
example will fail because SIZE_MAX is seen as -1.
Add comparison helpers that take tunable types into account and use
them to do comparison instead.
linux: Normalize and return timeout on select (BZ #27651)
The commit 2433d39b697, which added time64 support to select, changed
the function to use __NR_pselect6 (or __NR_pelect6_time64) on all
architectures. However, on architectures where the symbol was
implemented with __NR_select the kernel normalizes the passed timeout
instead of return EINVAL. For instance, the input timeval
{ 0, 5000000 } is interpreted as { 5, 0 }.
And as indicated by BZ #27651, this semantic seems to be expected
and changing it results in some performance issues (most likely
the program does not check the return code and keeps issuing
select with unormalized tv_usec argument).
To avoid a different semantic depending whether which syscall the
architecture used to issue, select now always normalize the timeout
input. This is a slight change for some ABIs (for instance aarch64).
Lukasz Majewski [Sat, 13 Mar 2021 22:34:21 +0000 (23:34 +0100)]
tst: Provide test for select
This change adds new test to assess select()'s timeout related
functionality (the rdfs set provides valid fd - stderr - but during
normal program operation there is no data to be read, so one just
waits for timeout).
To be more specific - two use cases are checked:
- if select() times out immediately when passed struct timeval has
zero values of tv_usec and tv_sec.
- if select() times out after timeout specified in passed argument
Szabolcs Nagy [Thu, 25 Feb 2021 14:49:58 +0000 (14:49 +0000)]
malloc: Fix a realloc crash with heap tagging [BZ 27468]
_int_free must be called with a chunk that has its tag reset. This was
missing in a rare case that could crash when heap tagging is enabled:
when in a multi-threaded process the current arena runs out of memory
during realloc, but another arena still has space to finish the realloc
then _int_free was called without clearing the user allocation tags.
Stefan Liebler [Tue, 23 Mar 2021 16:29:26 +0000 (17:29 +0100)]
S390: Also check vector support in memmove ifunc-selector [BZ #27511]
The arch13 memmove variant is currently selected by the ifunc selector
if the Miscellaneous-Instruction-Extensions Facility 3 facility bit
is present, but the function is also using vector instructions.
If the vector support is not present, one is receiving an operation
exception.
Therefore this patch also checks for vector support in the ifunc
selector and in ifunc-impl-list.c.
Just to be sure, the configure check is now also testing an arch13
vector instruction and an arch13 Miscellaneous-Instruction-Extensions
Facility 3 instruction.
DJ Delorie [Thu, 11 Mar 2021 17:50:02 +0000 (12:50 -0500)]
test-container: Always copy test-specific support files [BZ #27537]
There's a small chance that a fresh checkout will result in some of
the test-specific container files will have the same timestamp and
size, which breaks the rsync logic in test-container, resulting in
tests running with the wrong support files.
This patch changes the rsync logic to always copy the test-specific
files, which normally would always be copied anyway. The rsync logic
for the testroot itself is unchanged.
It is effectively used, unexcept for pthread_cond_destroy, where we do
not want it; see bug 27304. The internal locks do not support a
process-shared mode.
Jakub Jelinek [Thu, 4 Mar 2021 14:15:33 +0000 (15:15 +0100)]
pthread_once hangs when init routine throws an exception [BZ #18435]
This is another attempt at making pthread_once handle throwing exceptions
from the init routine callback. As the new testcases show, just switching
to the cleanup attribute based cleanup does fix the tst-once5 test, but
breaks the new tst-oncey3 test. That is because when throwing exceptions,
only the unwind info registered cleanups (i.e. C++ destructors or cleanup
attribute), when cancelling threads and there has been unwind info from the
cancellation point up to whatever needs cleanup both unwind info registered
cleanups and THREAD_SETMEM (self, cleanup, ...) registered cleanups are
invoked, but once we hit some frame with no unwind info, only the
THREAD_SETMEM (self, cleanup, ...) registered cleanups are invoked.
So, to stay fully backwards compatible (allow init routines without
unwind info which encounter cancellation points) and handle exception throwing
we actually need to register the pthread_once cleanups in both unwind info
and in the THREAD_SETMEM (self, cleanup, ...) way.
If an exception is thrown, only the former will happen and we in that case
need to also unregister the THREAD_SETMEM (self, cleanup, ...) registered
handler, because otherwise after catching the exception the user code could
call deeper into the stack some cancellation point, get cancelled and then
a stale cleanup handler would clobber stack and probably crash.
If a thread calling init routine is cancelled and unwind info ends before
the pthread_once frame, it will be cleaned up through self->cleanup as
before. And if unwind info is present, unwind_stop first calls the
self->cleanup registered handler for the frame, then it will call the
unwind info registered handler but that will already see __do_it == 0
and do nothing.
Florian Weimer [Mon, 15 Mar 2021 09:33:43 +0000 (10:33 +0100)]
elf: ld.so --help calls _dl_init_paths without a main map [BZ #27577]
In this case, use the link map of the dynamic loader itself as
a replacement. This is more than just a hack: if we ever support
DT_RUNPATH/DT_RPATH for the dynamic loader, reporting it for
ld.so --help (without further command line arguments) would be the
right thing to do.
Carlos O'Donell [Fri, 12 Mar 2021 15:44:47 +0000 (16:44 +0100)]
elf: Always set l in _dl_init_paths (bug 23462)
After d1d5471579eb0426671bf94f2d71e61dfb204c30 ("Remove dead
DL_DST_REQ_STATIC code.") we always setup the link map l to make the
static and shared cases the same. The bug is that in elf/dl-load.c
(_dl_init_paths) we conditionally set l only in the #ifdef SHARED
case, but unconditionally use it later. The simple solution is to
remove the #ifdef SHARED conditional, because it's no longer needed,
and unconditionally setup l for both the static and shared cases. A
regression test is added to run a static binary with
LD_LIBRARY_PATH='$ORIGIN' which crashes before the fix and runs after
the fix.
x86: Move x86 processor cache info to cpu_features
missed _SC_LEVEL1_ICACHE_LINESIZE.
1. Add level1_icache_linesize to struct cpu_features.
2. Initialize level1_icache_linesize by calling handle_intel,
handle_zhaoxin and handle_amd with _SC_LEVEL1_ICACHE_LINESIZE.
3. Return level1_icache_linesize for _SC_LEVEL1_ICACHE_LINESIZE.
io: Return EBAFD for negative file descriptor on fstat (BZ #27559)
Now that fstat is implemented on top fstatat we need to handle negative
inputs. The implementation now rejects AT_FDCWD, which would otherwise
be accepted by the kernel.
Checked on x86_64-linux-gnu and on i686-linux-gnu.
DJ Delorie [Thu, 25 Feb 2021 21:08:21 +0000 (16:08 -0500)]
nscd: Fix double free in netgroupcache [BZ #27462]
In commit 745664bd798ec8fd50438605948eea594179fba1 a use-after-free
was fixed, but this led to an occasional double-free. This patch
tracks the "live" allocation better.
H.J. Lu [Tue, 2 Feb 2021 21:45:58 +0000 (13:45 -0800)]
x86: Set minimum x86-64 level marker [BZ #27318]
Since the full ISA set used in an ELF binary is unknown to compiler,
an x86-64 ISA level marker indicates the minimum, not maximum, ISA set
required to run such an ELF binary. We never guarantee a library with
an x86-64 ISA level v3 marker doesn't contain other ISAs beyond x86-64
ISA level v3, like AVX VNNI. We check the x86-64 ISA level marker for
the minimum ISA set. Since -march=sandybridge enables only some ISAs
in x86-64 ISA level v3, we should set the needed ISA marker to v2.
Otherwise, libc is compiled with -march=sandybridge will fail to run on
Sandy Bridge:
$ ./elf/ld.so ./libc.so
./libc.so: (p) CPU ISA level is lower than required: needed: 7; got: 3
Set the minimum, instead of maximum, x86-64 ISA level marker should have
no impact on the glibc-hwcaps directory assignment logic in ldconfig nor
ld.so.
DJ Delorie [Thu, 18 Feb 2021 20:26:30 +0000 (15:26 -0500)]
nss: Re-enable NSS module loading after chroot [BZ #27389]
The glibc 2.33 release enabled /etc/nsswitch.conf reloading,
and to prevent potential security issues like CVE-2019-14271
the re-loading of nsswitch.conf and all mdoules was disabled
when the root filesystem changes (see bug 27077).
Unfortunately php-lpfm and openldap both require the ability
to continue to load NSS modules after chroot. The packages
do not exec after the chroot, and so do not cause the
protections to be reset. The only solution is to re-enable
only NSS module loading (not nsswitch.conf reloading) and so
get back the previous glibc behaviour.
In the future we may introduce a way to harden applications
so they do not reload NSS modules once the root filesystem
changes, or that only files/dns are available pre-loaded
(or builtin).
tunables: Disallow negative values for some tunables
The glibc.malloc.mmap_max tunable as well as al of the INT_32 tunables
don't have use for negative values, so pin the hardcoded limits in the
non-negative range of INT. There's no real benefit in any of those
use cases for the extended range of unsigned, so I have avoided added
a new type to keep things simple.
The TUNABLE_SET interface took a primitive C type argument, which
resulted in inconsistent type conversions internally due to incorrect
dereferencing of types, especialy on 32-bit architectures. This
change simplifies the TUNABLE setting logic along with the interfaces.
Now all numeric tunable values are stored as signed numbers in
tunable_num_t, which is intmax_t. All calls to set tunables cast the
input value to its primitive type and then to tunable_num_t for
storage. This relies on gcc-specific (although I suspect other
compilers woul also do the same) unsigned to signed integer conversion
semantics, i.e. the bit pattern is conserved. The reverse conversion
is guaranteed by the standard.
nsswitch: return result when nss database is locked [BZ #27343]
Before the change nss_database_check_reload_and_get() did not populate
the '*result' value when it returned success in a case of chroot
detection. This caused initgroups() to use garage pointer in the
following test (extracted from unbound):
```
int main() {
// load some NSS modules
struct passwd * pw = getpwnam("root");
chdir("/tmp");
chroot("/tmp");
chdir("/");
// access nsswitch.conf in a chroot
initgroups("root", 0);
}
```
elf: Fix tests that rely on ld.so.cache for cross-compiling
For configurations with cross-compiling equal to 'maybe' or 'no',
ldconfig will not run and thus the ld.so.cache will not be created
on the container testroot.pristine.
This lead to failures on both tst-glibc-hwcaps-prepend-cache and
tst-ldconfig-ld_so_conf-update on environments where the same
compiler can be used to build different ABIs (powerpc and x86 for
instance).
This patch addas a new test-container hook, ldconfig.run, that
triggers a ldconfig execution prior the test execution.
x86: Use HAS_CPU_FEATURE with IBT and SHSTK [BZ #26625]
broke
GLIBC_TUNABLES=glibc.cpu.hwcaps=-IBT,-SHSTK
since it can no longer disable IBT nor SHSTK. Handle IBT and SHSTK with:
1. Revert commit 94cd37ebb293321115a36a422b091fdb72d2fb08.
2. Clears the usable CET feature bits if kernel doesn't support CET.
3. Add GLIBC_TUNABLES tests without dlopen.
4. Add tests to verify that CPU_FEATURE_USABLE on IBT and SHSTK matches
_get_ssp.
5. Update GLIBC_TUNABLES tests with dlopen to verify that CET is disabled
with GLIBC_TUNABLES.
A not so recent kernel change[1] changed how the trampoline
`__kernel_sigtramp_rt64` is used to call signal handlers.
This was exposed on the test misc/tst-sigcontext-get_pc
Before kernel 5.9, the kernel set LR to the trampoline address and
jumped directly to the signal handler, and at the end the signal
handler, as any other function, would `blr` to the address set. In
other words, the trampoline was executed just at the end of the signal
handler and the only thing it did was call sigreturn. But since
kernel 5.9 the kernel set CTRL to the signal handler and calls to the
trampoline code, the trampoline then `bctrl` to the address in CTRL,
setting the LR to the next instruction in the middle of the
trampoline, when the signal handler returns, the rest of the
trampoline code executes the same code as before.
Here is the full trampoline code as of kernel 5.11.0-rc5 for
reference:
V_FUNCTION_BEGIN(__kernel_sigtramp_rt64)
.Lsigrt_start:
bctrl /* call the handler */
addi r1, r1, __SIGNAL_FRAMESIZE
li r0,__NR_rt_sigreturn
sc
.Lsigrt_end:
V_FUNCTION_END(__kernel_sigtramp_rt64)
This new behavior breaks how `backtrace()` uses to detect the
trampoline frame to correctly reconstruct the stack frame when it is
called from inside a signal handling.
This workaround rely on the fact that the trampoline code is at very
least two (maybe 3?) instructions in size (as it is in the 32 bits
version, only on `li` and `sc`), so it is safe to check the return
address be in the range __kernel_sigtramp_rt64 .. + 4.
projects / thirdparty / glibc.git / log
