Tmp2 #16
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Tmp2 #16
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The following sequence of actions was happening which caused a null pointer dereference: 1. debug_backtrace() returns an array 2. The concatenation to $c will transform the array to a string via `zval_get_string_func` for op2 and output a warning. Note that zval op1 is of type string due to the first do-while sequence. 3. The warning of an implicit "array to string conversion" triggers the ob_start callback to run. This code transform $c (==op1) to a long. 4. The code below the 2 do-while sequences assume that both op1 and op2 are strings, but this is no longer the case. A dereference of the string will therefore result in a null pointer dereference. The solution used here is to work with the zend_string directly instead of with the ops.
Co-authored-by: changochen1@gmail.com
Co-authored-by: cmbecker69@gmx.de Co-authored-by: yukik@risec.co.jp
This tests the path op1_string_from_func == true, result == op1, op1 == op2 in the do-while, which wasn't tested before.
This tests for the case where result == op1, op1 != op2 and op1_string and op2_string are non-interned strings that are equal.
nielsdos
pushed a commit
that referenced
this pull request
Oct 13, 2024
even without sanitizers, it is reproducible but with the following
```
<?php
$g = gmp_init(256);
var_dump(gmp_pow($g, PHP_INT_MAX));
```
we get this
```
AddressSanitizer:DEADLYSIGNAL
=================================================================
==286922==ERROR: AddressSanitizer: FPE on unknown address 0x03e8000460ca (pc 0x7faf6c69de5c bp 0x400000000000004 sp 0x7ffe9843c740 T0)
#0 0x7faf6c69de5c in __pthread_kill_implementation nptl/pthread_kill.c:44
#1 0x7faf6c649c81 in __GI_raise ../sysdeps/posix/raise.c:26
#2 0x7faf6db9386c in __gmp_exception (/lib/x86_64-linux-gnu/libgmp.so.10+0xd86c) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#3 0x7faf6db938d3 in __gmp_overflow_in_mpz (/lib/x86_64-linux-gnu/libgmp.so.10+0xd8d3) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#4 0x7faf6dbac95c in __gmpz_realloc (/lib/x86_64-linux-gnu/libgmp.so.10+0x2695c) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#5 0x7faf6dba9038 in __gmpz_n_pow_ui (/lib/x86_64-linux-gnu/libgmp.so.10+0x23038) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#6 0x5565ae1ccd9f in zif_gmp_pow /home/dcarlier/Contribs/php-src/ext/gmp/gmp.c:1286
#7 0x5565aee96ea9 in ZEND_DO_ICALL_SPEC_RETVAL_USED_HANDLER /home/dcarlier/Contribs/php-src/Zend/zend_vm_execute.h:1312
#8 0x5565af144320 in execute_ex /home/dcarlier/Contribs/php-src/Zend/zend_vm_execute.h:56075
#9 0x5565af160f07 in zend_execute /home/dcarlier/Contribs/php-src/Zend/zend_vm_execute.h:60439
#10 0x5565aed6fafe in zend_execute_scripts /home/dcarlier/Contribs/php-src/Zend/zend.c:1842
#11 0x5565aeae70a8 in php_execute_script /home/dcarlier/Contribs/php-src/main/main.c:2578
#12 0x5565af532f4e in do_cli /home/dcarlier/Contribs/php-src/sapi/cli/php_cli.c:964
#13 0x5565af535877 in main /home/dcarlier/Contribs/php-src/sapi/cli/php_cli.c:1334
#14 0x7faf6c633d67 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
#15 0x7faf6c633e24 in __libc_start_main_impl ../csu/libc-start.c:360
#16 0x5565adc04040 in _start (/home/dcarlier/Contribs/php-src/sapi/cli/php+0x2604040) (BuildId: 949049955bdf8b7197390b1978a1dfc3ef6fdf38)
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: FPE nptl/pthread_kill.c:44 in __pthread_kill_implementation
==286922==ABORTING
```
nielsdos
pushed a commit
that referenced
this pull request
Oct 26, 2024
even without sanitizers, it is reproducible but with the following
```
<?php
$g = gmp_init(256);
var_dump(gmp_pow($g, PHP_INT_MAX));
```
we get this
```
AddressSanitizer:DEADLYSIGNAL
=================================================================
==286922==ERROR: AddressSanitizer: FPE on unknown address 0x03e8000460ca (pc 0x7faf6c69de5c bp 0x400000000000004 sp 0x7ffe9843c740 T0)
#0 0x7faf6c69de5c in __pthread_kill_implementation nptl/pthread_kill.c:44
#1 0x7faf6c649c81 in __GI_raise ../sysdeps/posix/raise.c:26
#2 0x7faf6db9386c in __gmp_exception (/lib/x86_64-linux-gnu/libgmp.so.10+0xd86c) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#3 0x7faf6db938d3 in __gmp_overflow_in_mpz (/lib/x86_64-linux-gnu/libgmp.so.10+0xd8d3) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#4 0x7faf6dbac95c in __gmpz_realloc (/lib/x86_64-linux-gnu/libgmp.so.10+0x2695c) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#5 0x7faf6dba9038 in __gmpz_n_pow_ui (/lib/x86_64-linux-gnu/libgmp.so.10+0x23038) (BuildId: 1af68a49fe041a5bb48a2915c3d47541f713bb38)
#6 0x5565ae1ccd9f in zif_gmp_pow /home/dcarlier/Contribs/php-src/ext/gmp/gmp.c:1286
#7 0x5565aee96ea9 in ZEND_DO_ICALL_SPEC_RETVAL_USED_HANDLER /home/dcarlier/Contribs/php-src/Zend/zend_vm_execute.h:1312
#8 0x5565af144320 in execute_ex /home/dcarlier/Contribs/php-src/Zend/zend_vm_execute.h:56075
#9 0x5565af160f07 in zend_execute /home/dcarlier/Contribs/php-src/Zend/zend_vm_execute.h:60439
#10 0x5565aed6fafe in zend_execute_scripts /home/dcarlier/Contribs/php-src/Zend/zend.c:1842
#11 0x5565aeae70a8 in php_execute_script /home/dcarlier/Contribs/php-src/main/main.c:2578
#12 0x5565af532f4e in do_cli /home/dcarlier/Contribs/php-src/sapi/cli/php_cli.c:964
#13 0x5565af535877 in main /home/dcarlier/Contribs/php-src/sapi/cli/php_cli.c:1334
#14 0x7faf6c633d67 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58
#15 0x7faf6c633e24 in __libc_start_main_impl ../csu/libc-start.c:360
#16 0x5565adc04040 in _start (/home/dcarlier/Contribs/php-src/sapi/cli/php+0x2604040) (BuildId: 949049955bdf8b7197390b1978a1dfc3ef6fdf38)
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: FPE nptl/pthread_kill.c:44 in __pthread_kill_implementation
==286922==ABORTING
```
close phpGH-16384
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