The problem can happen when dfi_s390mv_init_gen() returns with an error
code to dfi_init() in dfi.c.
Double free condition occurs on zg_close() call at the end of the
while loop in dfi_init() if zg_close() has already been called for the
same file handle at the end of open_dump() function in scope of
dfi_s390mv_init_gen() processing.
This global file handle is not closed during init() call for any
other dump formats. Since it is not reopened/reused after open_dump() call
during multi-volume dump initialization, we should not close it at all.
The problem can be reproduced in the following steps:
1) Install multi-volume dump tool
# zipl -M mvdump.conf
Dump target: 2 partitions with a total size of 4732 MB.
Warning: All information on the following partitions will be lost!
/dev/dasdb2
/dev/dasdb3
Do you want to continue creating multi-volume dump partitions (y/n)?y
Done.
2) Run zgetdump -i using device (not partition) as a parameter without
taking actual dump.
# zgetdump -i /dev/dasdb
free(): double free detected in tcache 2
Aborted (core dumped)
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This commit makes zgetdump work with /dev/mem again.
zg_seek() should not attempt to verify the given offset for devices before
issuing lseek() because special devices like /dev/mem report 0 in
stat.sb_size.
$ zgetdump -i /dev/mem
zgetdump: Trying to seek past file end "/dev/mem"
Fixes: 11e78cada5 ("zdump: catch attempts to seek past end of file in zg_seek()")
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This change allows mocking of print macros in unit tests.
Being able to do this in unit tests, enables us to catch output from
zgetdump functions and test it.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
_zg_err_errno() should save the current errno value before calling any
libc functions because they could change it. Failing to do so, may result
in _zg_err_errno() displaying an incorrect error message.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This change allows mocking of error/abort macros in unit tests.
Being able to do this in unit tests, enables us to test error conditions w/o
terminating the unit test runner.
The new error functions do not have "noreturn" attribute because
this would make mocking of them in unit tests impossible. We must not
compile these functions as noreturn because we need to return from them
in unit tests and returning from a noreturn function is an undefined
behavior in the C++ standard!
For more details:
- ISO/IEC 14882:2017, Chapter 10.6.8 "Noreturn attribute""
- https://en.cppreference.com/w/cpp/language/attributes/noreturn.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
It is unusual to write the file output from a tool to stdout. Therefore
add a positional argument to the zgetdump convert action where the
output file can be specified. If no positional argument is given the
output is written to stdout as before and therefore there is no change
in the default behavior.
If the file output already exists an error is returned. The reason for
this is to avoid the situation where an existing dump is accidentally
overwritten by the user.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The keyword extern before a function declaration is not required with
modern C compilers.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The primary goal of this change is to split DFO ELF module into
multiple smaller ones for better unit testability.
The change doesn't introduce any functionality changes, just shuffling code
around.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Reviewed-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The primary goal is to separate DFO code into multiple smaller modules
and make it unit testable.
This refactoring only moved the code around w/o changing any functionality.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
...to make clear why `off` is initialized to 0 and that all calls to
`dfo_chunk_add` occur for the same reason. For consistency reasons adapt
the `off` value calculation as well.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Rename the parameter `ptr` of `notes_init` to something meaningful. Since
it points to the start of the notes segment rename it to `segment_start`.
In addition, improve the documentation for the function.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Use `mem_chunk->size` instead of recalculate it. In addition, assign
`p_vaddr` to `p_paddr` to make clear that they must be equal and rename the
parameter `load_offset` to `elf_offset` to make clear that the offset in
the ELF vmcore file is meant. Finally rename `loads_init` to
`load_phdrs_init`.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This cast makes the macros easier to use without getting compiler warnings.
e.g.
dfo_elf.c: In function 'dfo_elf_init':
dfo_elf.c:343:20: warning: assignment to 'Elf64_Phdr *' from incompatible pointer type 'char *' [-Wincompatible-pointer-types]
343 | phdrs_load = PTR_ADD(phdr_notes, sizeof(Elf64_Phdr) * phdrs_notes_count);
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
With an upcoming patch the output target can be different to `stdout`.
Therefore, the term `ZG_ACTION_STDOUT` is no longer generic enough. In addition,
rename `do_write` to `do_copy` to match the enum name.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Currently, for some commands (e.g. `zgetdump unmount`) unused positional
arguments are silently ignored, for some commands (`zgetdump mount`) they're
not. Therefore let's fix this by always returning an error message and exit code
if too many positional arguments are given.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Don't include dfi_mem_chunk.h in dfi.h because not every module including
dfi.h needs it.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Separate the definition of a struct from the declaration of a global
variable of the type. To improve readability.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Create a separate C header for STDOUT to separate independent things and
make it more readable.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Set DFO format after the parsing of command-line arguments is done.
The command-line argument parsing should be independent of DFO.
This improves testability of the command-line argument parsing and
separates independent things from each other.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Make the C module responsible for the parsing of command-line arguments
independent of other global variables. This improves its testability.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Get rid of C headers which include everything. This is bad for testing and
maintainability. C files should include only what they need and no more.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Create a separate C header for FUSE to separate independent things and
make it more readable.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Create a separate C header for DFI VMCOREINFO to separate
independent things and make it more readable.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Replace magic values with descriptive names to improve readability.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
To prevent segmentation faults when the function dfi_mem_phys_read() is
given invalid parameters, check that the given memory range falls within
a known physical memory chunk, just like it is done for dfi_mem_virt_read().
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The new name describes the purpose of the function better and
emphasizes its difference with the function dfi_mem_phys_read().
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Always use the function dfi_mem_read_rc() which verifies that the given
address and size fall within a valid memory chunk. We cannot trust
user's input.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The function dfi_mem_chunk_virt_add() is used only internally and should
not be exported to prevent misuse.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
The keyword extern is redundant for function declarations in C headers.
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
zgetdump is for analyzing VM coredumps and not user space coredumps therefore
return an error in case of a user space coredump.
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This fixes the following Valgrind finding:
==28040== Syscall param rt_sigaction(act->sa_flags) points to uninitialised byte(s)
==28040== at 0x48C98B0: __libc_sigaction (sigaction.c:58)
==28040== by 0x10D507: sig_handler_init (zgetdump.c:58)
==28040== by 0x10D507: main (zgetdump.c:179)
==28040== Address 0x1ffefffc84 is on thread 1's stack
==28040== in frame #0, created by __libc_sigaction (sigaction.c:43)
Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Sanity check ELF notes descriptor size before reading it. This prevents
stack buffer overflows in case a dump contains invalid ELF notes.
Instead of reading a note's descriptor into a temporary buffer on stack,
read it directly into the buffer given to nt_read() but also provide
a maximum length of the given buffer to nt_read() in order to prevent
overflows.
This problem was found with valgrind and AFL fuzzing + ASAN.
AFL + ASAN findings:
[root@t83lp49 s390-tools]# ./zdump/zgetdump -iVVVVV ~/zgetdump-fuzzing/findings/crashes/id\:000008\,sig\:06\,src\:000007\,op\:arith8\,pos\:67\,val\:+3
TRACE: DFI initialization
DEBUG: DFI trying s390tape
DEBUG: DFI s390tape returned with rc -19
DEBUG: DFI trying devmem
DEBUG: DFI devmem returned with rc -19
DEBUG: DFI trying s390mv_ext
DEBUG: DFI s390mv_ext returned with rc -19
DEBUG: DFI trying s390mv
DEBUG: DFI s390mv returned with rc -19
DEBUG: DFI trying s390_ext
DEBUG: DFI S390 extended initialization
DEBUG: DFI s390_ext returned with rc -19
DEBUG: DFI trying s390
DEBUG: DFI S390 initialization
DEBUG: DFI s390 returned with rc -19
DEBUG: DFI trying lkcd
DEBUG: DFI lkcd returned with rc -19
DEBUG: DFI trying elf
DEBUG: DFI ELF initialization
DEBUG: DFI ELF e_phnum 11
DEBUG: DFI ELF p_type[0] 0x4
DEBUG: DFI ELF n_type 0x0
AddressSanitizer:DEADLYSIGNAL
=================================================================
==208548==ERROR: AddressSanitizer: stack-overflow on address 0x03ffef05d000 (pc 0x0000010051b0 bp 0x03fff107dc40 sp 0x03ffef05dac8 T0)
#0 0x10051b0 (/root/s390-tools/zdump/zgetdump+0x10051b0)
SUMMARY: AddressSanitizer: stack-overflow (/root/s390-tools/zdump/zgetdump+0x10051b0)
==208548==ABORTING
valgrind findings:
==56423== Source and destination overlap in memcpy(0x4a86d38, 0x4a875e0, 4096)
==56423== at 0x4839F86: memcpy (in /usr/lib/s390x-linux-gnu/valgrind/vgpreload_memcheck-s390x-linux.so)
==56423== by 0x114253: memcpy (string_fortified.h:34)
==56423== by 0x114253: nt_read (dfi_elf.c:95)
==56423== by 0x1145FF: nt_s390_prefix_read (dfi_elf.c:195)
==56423== by 0x1145FF: pt_notes_add (dfi_elf.c:259)
==56423== by 0x1145FF: dfi_elf_init (dfi_elf.c:326)
==56423== by 0x112A57: dfi_init (dfi.c:1212)
==56423== by 0x10D663: do_dump_info (zgetdump.c:127)
==56423== by 0x10D663: main (zgetdump.c:182)
==56423==
==56423== Invalid write of size 8
==56423== at 0x4839E28: memcpy (in /usr/lib/s390x-linux-gnu/valgrind/vgpreload_memcheck-s390x-linux.so)
==56423== by 0x114253: memcpy (string_fortified.h:34)
==56423== by 0x114253: nt_read (dfi_elf.c:95)
==56423== by 0x1145FF: nt_s390_prefix_read (dfi_elf.c:195)
==56423== by 0x1145FF: pt_notes_add (dfi_elf.c:259)
==56423== by 0x1145FF: dfi_elf_init (dfi_elf.c:326)
==56423== by 0x112A57: dfi_init (dfi.c:1212)
==56423== by 0x10D663: do_dump_info (zgetdump.c:127)
==56423== by 0x10D663: main (zgetdump.c:182)
==56423== Address 0x4a86ee0 is 0 bytes after a block of size 912 alloc'd
==56423== at 0x483675E: calloc (in /usr/lib/s390x-linux-gnu/valgrind/vgpreload_memcheck-s390x-linux.so)
==56423== by 0x10E71D: zg_alloc (zg.c:93)
==56423== by 0x114793: nt_prstatus_read (dfi_elf.c:123)
==56423== by 0x114793: pt_notes_add (dfi_elf.c:234)
==56423== by 0x114793: dfi_elf_init (dfi_elf.c:326)
==56423== by 0x112A57: dfi_init (dfi.c:1212)
==56423== by 0x10D663: do_dump_info (zgetdump.c:127)
==56423== by 0x10D663: main (zgetdump.c:182)
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Suggested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Reported-by: Steffen Eiden <seiden@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
