7 Commits

Author SHA1 Message Date
Mikhail Zaslonko
a8a87779c0 zdump/dfi_lkcd: Validate LKCD page address against mem_end
mem_init_flex() allocates the page header index array sized for
ADDR_TO_IDX(mem_end) + 1 entries, but never checked that each
page record's address falls within [0, mem_end).
A crafted LKCD page record with addr >= mem_end writes 8 bytes
beyond the allocation.

Fix by rejecting any page record whose address is > mem_end - PAGE_SIZE
with ERR_EXIT(), immediately after the end-of-dump marker check.

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>
2026-07-20 15:25:59 +02:00
Mikhail Zaslonko
cdabf280ac zdump/dfi_lkcd: Validate LKCD page size before buffer read
read_page_buf() uses the file-controlled pg_hdr->size directly as the
byte count for zg_read() into fixed stack buffers of PAGE_SIZE.
A crafted LKCD dump with pg_hdr->size > PAGE_SIZE overflows the buffer
and smashes the stack frame. A size of 0 for a raw page silently
produces uninitialised data.

Enforce page header size constraints following crash-utility's logic:
- Compressed or Raw pages with size > PAGE_SIZE are invalid;
  exit with an error.
- Raw pages with size 0 contain no data in the file; fill the
  output buffer with zeros without reading.
- Compressed pages with size 0 are caught by the uncompress() return
  code check.
- Raw pages with size != PAGE_SIZE are invalid; exit with an error.

Check the return code of uncompress() and exit with an error if
decompression fails, rather than silently proceeding with an incomplete
output buffer.

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>
2026-07-20 15:25:59 +02:00
Mikhail Zaslonko
f821a3c174 zdump: Drop support of 32-bit dump architecture
- Initialize dump and dump-tool architecture to DFI_ARCH_64 at the start
  of dfi_init() and dt_init() respectively.
- Bail out if any dump architecture other than ARCH_64 has been detected
  in s390_ext or s390mv_ext DASD dump header.
- Remove redundant dfi_arch_set() and dt_arch_set() functions.
- Get rid of l.arch local variables in dfi* and dt* source files and
  drop dfi_arch() function.
- Drop the usage of DFI_ARCH_32 and compeletely remove DFI_ARCH_UNKNOWN.
- Drop special register and lowcore processing functions used
  for DFI_ARCH_32.
- Drop df_s390_from_dfi_arch() and df_s390_to_dfi_arch() funcitons.
- Update the man file for zgetdump.

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>
2025-04-07 17:42:18 +02:00
Alexander Egorenkov
353c23a157 zdump: Include dfi_mem_chunk.h only if required
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>
2021-11-10 15:12:10 +01:00
Alexander Egorenkov
1005e7be7e zdump: Don't use god-like C headers
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>
2021-11-10 15:12:10 +01:00
Alexander Egorenkov
f15e32cdb1 zdump/dfi: Fix illegal memory access in dfi_cpu_add_from_lc()
Check that a CPU's lowcore address falls within a valid memory region
before accessing it. This prevents potential illegal memory accesses
in case a dump contains invalid CPU lowcore addresses.

This bug was found with AFL fuzzing and ASAN.

Starting program: /root/s390-tools/zdump/zgetdump -iVVVVV /root/zgetdump-fuzzing/findings/crashes/id:000004,sig:06,src:000005,op:flip32,pos:3055
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
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
 INFO: DFI S390 version 5
DEBUG: DFI S390 mem_size 0x00000000000dbba0
DEBUG: DFI add vol mem chunk start 0x0000000000000000 size 0x00000000000dbba0 volnr 0

[snip]

TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x0000000000000000 size 0x0000000000002000
TRACE: DFI virt mem read addr 0x00000000000000ff size 0x0000000000002000
TRACE: DFI virt mem read addr 0x00000000ffffff00 size 0x0000000000002000

Program received signal SIGSEGV, Segmentation fault.
0x000000000100fbb0 in mem_read (cnt=<optimized out>, buf=0x3ffffffc7d0, addr=4294967040, mem=0x104b218 <l+152>) at dfi.c:339
339                     size = MIN(cnt - copied, mem_chunk->end - addr + 1);
Missing separate debuginfos, use: dnf debuginfo-install fuse-libs-2.9.9-11.fc34.s390x glibc-2.33-20.1.ibm.fc34.s390x libasan-11.0.1-0.3.1.ibm.fc34.s390x libgcc-11.0.1-0.3.1.ibm.fc34.s390x libstdc++-11.0.1-0.3.1.ibm.fc34.s390x zlib-1.2.11-26.fc34.s390x
(gdb) bt

Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
2021-10-01 14:59:56 +02:00
Michael Holzheu
b627b8d8e1 Initial s390-tools-2.0.0 import
This commit is based on the s390-tools-1.39.0 version.

Changes on top of s390-tools-1.39.0:

 - Add MIT license to all source files
 - Add LICENSE file
 - Transform REAMDE to README.md (markdown)
 - Add AUTHORS.md file
 - Add CONTRIBUTING.md file
 - Move changelog from README to CHANGELOG.md file

Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
2017-08-21 10:55:40 +02:00