Closed
Description
Description
The following code:
<?php
class C {
function __serialize() {
$_SESSION = [];
return [];
}
}
session_start();
$_SESSION['Lz'] = new C;
for ($i = 0; $i < 100000; $i++) {
$_SESSION[(string) $i] = $i;
}
session_encode();
Resulted in this output:
==955137==ERROR: AddressSanitizer: heap-use-after-free on address 0x60600002b6a8 at pc 0x56065667c667 bp 0x7ffc00fa4570 sp 0x7ffc00fa4568
READ of size 4 at 0x60600002b6a8 thread T0
#0 0x56065667c666 in ps_srlzr_encode_php /tmp/php-asan/ext/session/session.c:1086:2
#1 0x56065668a72d in php_session_encode /tmp/php-asan/ext/session/session.c:281:10
#2 0x56065668bdfe in zif_session_encode /tmp/php-asan/ext/session/session.c:2586:8
#3 0x56065714ebc2 in ZEND_DO_ICALL_SPEC_RETVAL_UNUSED_HANDLER /tmp/php-asan/Zend/zend_vm_execute.h:1299:2
#4 0x560656fb183d in execute_ex /tmp/php-asan/Zend/zend_vm_execute.h:58565:7
#5 0x560656fb2067 in zend_execute /tmp/php-asan/Zend/zend_vm_execute.h:64217:2
#6 0x5606573e6860 in zend_execute_script /tmp/php-asan/Zend/zend.c:1932:3
#7 0x560656c04d2b in php_execute_script_ex /tmp/php-asan/main/main.c:2574:13
#8 0x560656c05228 in php_execute_script /tmp/php-asan/main/main.c:2614:9
#9 0x5606573ee309 in do_cli /tmp/php-asan/sapi/cli/php_cli.c:935:5
#10 0x5606573eb32c in main /tmp/php-asan/sapi/cli/php_cli.c:1310:18
#11 0x7fe68da29d8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
#12 0x7fe68da29e3f in __libc_start_main csu/../csu/libc-start.c:392:3
#13 0x560655e02de4 in _start (/workspaces/TriFuzz/targets/php-asan/bin/php+0x402de4)
0x60600002b6a8 is located 8 bytes inside of 56-byte region [0x60600002b6a0,0x60600002b6d8)
freed by thread T0 here:
#0 0x560655e87702 in free /opt/llvm-15-build/llvm-15.x/final/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:52:3
#1 0x560656e418a3 in __zend_free /tmp/php-asan/Zend/zend_alloc.c:3308:2
#2 0x560656e45774 in _efree /tmp/php-asan/Zend/zend_alloc.c:2747:3
#3 0x56065726154d in zend_array_destroy /tmp/php-asan/Zend/zend_hash.c:1866:2
#4 0x5606573c75b6 in rc_dtor_func /tmp/php-asan/Zend/zend_variables.c:57:2
#5 0x5606571f6a84 in zend_assign_to_variable /tmp/php-asan/Zend/zend_execute.h:179:4
#6 0x560656feb12d in ZEND_ASSIGN_SPEC_VAR_CONST_RETVAL_UNUSED_HANDLER /tmp/php-asan/Zend/zend_vm_execute.h:25239:11
#7 0x560656fb183d in execute_ex /tmp/php-asan/Zend/zend_vm_execute.h:58565:7
#8 0x560656f8d1ac in zend_call_function /tmp/php-asan/Zend/zend_execute_API.c:996:3
#9 0x560656f8f3b2 in zend_call_known_function /tmp/php-asan/Zend/zend_execute_API.c:1090:23
#10 0x560656b7219a in zend_call_known_instance_method /tmp/php-asan/Zend/zend_API.h:860:2
#11 0x560656b7210b in zend_call_known_instance_method_with_0_params /tmp/php-asan/Zend/zend_API.h:866:2
#12 0x560656b70778 in php_var_serialize_call_magic_serialize /tmp/php-asan/ext/standard/var.c:850:2
#13 0x560656b6833d in php_var_serialize_intern /tmp/php-asan/ext/standard/var.c:1147:10
#14 0x560656b67501 in php_var_serialize /tmp/php-asan/ext/standard/var.c:1321:2
#15 0x56065667c910 in ps_srlzr_encode_php /tmp/php-asan/ext/session/session.c:1086:2
#16 0x56065668a72d in php_session_encode /tmp/php-asan/ext/session/session.c:281:10
#17 0x56065668bdfe in zif_session_encode /tmp/php-asan/ext/session/session.c:2586:8
#18 0x56065714ebc2 in ZEND_DO_ICALL_SPEC_RETVAL_UNUSED_HANDLER /tmp/php-asan/Zend/zend_vm_execute.h:1299:2
#19 0x560656fb183d in execute_ex /tmp/php-asan/Zend/zend_vm_execute.h:58565:7
#20 0x560656fb2067 in zend_execute /tmp/php-asan/Zend/zend_vm_execute.h:64217:2
#21 0x5606573e6860 in zend_execute_script /tmp/php-asan/Zend/zend.c:1932:3
#22 0x560656c04d2b in php_execute_script_ex /tmp/php-asan/main/main.c:2574:13
#23 0x560656c05228 in php_execute_script /tmp/php-asan/main/main.c:2614:9
#24 0x5606573ee309 in do_cli /tmp/php-asan/sapi/cli/php_cli.c:935:5
#25 0x5606573eb32c in main /tmp/php-asan/sapi/cli/php_cli.c:1310:18
#26 0x7fe68da29d8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
previously allocated by thread T0 here:
#0 0x560655e879ae in malloc /opt/llvm-15-build/llvm-15.x/final/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:69:3
#1 0x560656e45ce3 in __zend_malloc /tmp/php-asan/Zend/zend_alloc.c:3280:14
#2 0x560656e45670 in _emalloc /tmp/php-asan/Zend/zend_alloc.c:2737:10
#3 0x56065724a027 in _zend_new_array /tmp/php-asan/Zend/zend_hash.c:291:18
#4 0x560656691fe3 in php_session_track_init /tmp/php-asan/ext/session/session.c:269:2
#5 0x56065667f824 in php_session_initialize /tmp/php-asan/ext/session/session.c:489:2
#6 0x56065667efd4 in php_session_start /tmp/php-asan/ext/session/session.c:1704:6
#7 0x56065668d0de in zif_session_start /tmp/php-asan/ext/session/session.c:2687:2
#8 0x56065714ebc2 in ZEND_DO_ICALL_SPEC_RETVAL_UNUSED_HANDLER /tmp/php-asan/Zend/zend_vm_execute.h:1299:2
#9 0x560656fb183d in execute_ex /tmp/php-asan/Zend/zend_vm_execute.h:58565:7
#10 0x560656fb2067 in zend_execute /tmp/php-asan/Zend/zend_vm_execute.h:64217:2
#11 0x5606573e6860 in zend_execute_script /tmp/php-asan/Zend/zend.c:1932:3
#12 0x560656c04d2b in php_execute_script_ex /tmp/php-asan/main/main.c:2574:13
#13 0x560656c05228 in php_execute_script /tmp/php-asan/main/main.c:2614:9
#14 0x5606573ee309 in do_cli /tmp/php-asan/sapi/cli/php_cli.c:935:5
#15 0x5606573eb32c in main /tmp/php-asan/sapi/cli/php_cli.c:1310:18
#16 0x7fe68da29d8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
SUMMARY: AddressSanitizer: heap-use-after-free /tmp/php-asan/ext/session/session.c:1086:2 in ps_srlzr_encode_php
Shadow bytes around the buggy address:
0x0c0c7fffd680: 00 00 00 00 00 00 00 fa fa fa fa fa fd fd fd fd
0x0c0c7fffd690: fd fd fd fa fa fa fa fa fd fd fd fd fd fd fd fd
0x0c0c7fffd6a0: fa fa fa fa 00 00 00 00 00 00 00 00 fa fa fa fa
0x0c0c7fffd6b0: fd fd fd fd fd fd fd fd fa fa fa fa fd fd fd fd
0x0c0c7fffd6c0: fd fd fd fd fa fa fa fa fd fd fd fd fd fd fd fd
=>0x0c0c7fffd6d0: fa fa fa fa fd[fd]fd fd fd fd fd fa fa fa fa fa
0x0c0c7fffd6e0: fd fd fd fd fd fd fd fa fa fa fa fa 00 00 00 00
0x0c0c7fffd6f0: 00 00 00 00 fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fffd700: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fffd710: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
0x0c0c7fffd720: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
==955137==ABORTING
PHP Version
PHP 8.5.0-dev
Operating System
No response