A SIGSEGV (SEGV_MAPERR) crash occurs when decode data

[fzzwork]

The language of MMKV

Java

The version of MMKV

v1.2.12

The platform of MMKV

Android

The installation of MMKV

Maven

What's the issue?

A SIGSEGV (SEGV_MAPERR) null pointer exception occurs when the trim() method is called.

CRASHSTACK

//堆栈1：decodeInt 0 #00 pc 000000000002889c partialLoadFromFile (/data/orange-ci/workspace/Core/MMKV_IO.cpp:390 [Inline: memcpy]) [arm64-v8a] 1 #01 pc 0000000000028e38 checkLoadData (/data/orange-ci/workspace/Core/MMKV_IO.cpp:293) [arm64-v8a] 2 #02 pc 0000000000029e24 getDataForKey (/data/orange-ci/workspace/Core/MMKV_IO.cpp:466) [arm64-v8a] 3 #03 pc 000000000001f538 getInt32 (/data/orange-ci/workspace/Core/MMKV.cpp:634) [arm64-v8a] 4 #04 pc 0000000000018748 decodeInt (../../../../src/main/cpp/native-bridge.cpp:393) [arm64-v8a]

//堆栈2：containsKey 0 #00 pc 000000000002889c partialLoadFromFile (/data/orange-ci/workspace/Core/MMKV_IO.cpp:390 [Inline: memcpy]) [] 1 #01 pc 0000000000028e38 checkLoadData (/data/orange-ci/workspace/Core/MMKV_IO.cpp:293) [] 2 #02 pc 00000000000201f4 containsKey (/data/orange-ci/workspace/Core/MMKV.cpp:790) [] 3 #03 pc 0000000000019a64 containsKey (../../../../src/main/cpp/native-bridge.cpp:532) [] 4 #04 pc 000000000052a040 art_jni_trampoline+160

//堆栈3：decodeString 0 #00 pc 000000000002889c partialLoadFromFile (/data/orange-ci/workspace/Core/MMKV_IO.cpp:390 [Inline: memcpy]) [arm64-v8a] 1 #01 pc 0000000000028e38 checkLoadData (/data/orange-ci/workspace/Core/MMKV_IO.cpp:293) [arm64-v8a] 2 #02 pc 0000000000029e24 getDataForKey (/data/orange-ci/workspace/Core/MMKV_IO.cpp:466) [arm64-v8a] 3 #03 pc 000000000001ecc0 getString (/data/orange-ci/workspace/Core/MMKV.cpp:545) [arm64-v8a] 4 #04 pc 0000000000019054 decodeString (../../../../src/main/cpp/native-bridge.cpp:472) [arm64-v8a]

//tomb.txt（对应堆栈3）
Build fingerprint: HUAWEI/LNA-AL00/HWLNA:12/HUAWEILNA-AL00/104.0.0.118C00:user/release-keys
Revision: 0
ABI: arm64
time: 2023-11-29 14:34:41
pid: 22461, tid: 24337, name: thread_sp_norma >>> com.xxx.app:MSF <<<
signal: 11 (SIGSEGV), code: 1 (SEGV_MAPERR) fault addr: 0x0
si_errno:0, si_errnoMsg:Success, sending pid:0, sending uid:0
r0: 0xb4000074a555a680 r1: 0x00000074b80c8fb0 r2: 0x0000000000000001
r3: 0x0000000000000000 r4: 0x0000000000000000 r5: 0xb4000074481f8957
r6: 0x0000000000000000 r7: 0x0000000000000000 r8: 0xb40000744f3bdaa0
r9: 0xb4000074470815e0 r10: 0x0000000000000000 r11: 0x0000000000000003
r12: 0x0000000000000000 r13: 0x00000000000dd968 r14: 0x0000000000080100
r15: 0x00000000ebad6a89 r16: 0x000000755b7cdf48 r17: 0x000000755b75aedc
r18: 0x00000074b4c4e000 r19: 0xb4000074a555a680 r20: 0x0000000000000000
r21: 0xb4000074a5701ce0 r22: 0xb4000074a5701ce0 r23: 0x00000074b80ca000
r24: 0x00000074b80c9160 r25: 0x00000074b80c9360 r26: 0x00000074b80c9374
r27: 0x00000074b80c9360 r28: 0x00000074b80c9250 r29: 0x00000074b80c9030
r30: 0x0000007434eede3c sp: 0x00000074b80c8fe0 pc: 0x0000007434eed89c
pstate: 0x0000000060001000
#00 pc 000000000002889c /data/app/~~e59sdqQ-X9HLkOm8B7xjCg==/com.xxx.app-Oryk7nRdrG9nJQza7heSYA==/lib/arm64/libmmkv.so [arm64-v8a::b18c4565b236796eefe43cb651009b06]
#1 pc 0000000000028e38 /data/app/~~e59sdqQ-X9HLkOm8B7xjCg==/com.xxx.app-Oryk7nRdrG9nJQza7heSYA==/lib/arm64/libmmkv.so [arm64-v8a::b18c4565b236796eefe43cb651009b06]
#2 pc 0000000000029e24 /data/app/~~e59sdqQ-X9HLkOm8B7xjCg==/com.xxx.app-Oryk7nRdrG9nJQza7heSYA==/lib/arm64/libmmkv.so [arm64-v8a::b18c4565b236796eefe43cb651009b06]
#3 pc 000000000001ecc0 /data/app/~~e59sdqQ-X9HLkOm8B7xjCg==/com.xxx.app-Oryk7nRdrG9nJQza7heSYA==/lib/arm64/libmmkv.so [arm64-v8a::b18c4565b236796eefe43cb651009b06]
#4 pc 0000000000019054 /data/app/~~e59sdqQ-X9HLkOm8B7xjCg==/com.xxx.app-Oryk7nRdrG9nJQza7heSYA==/lib/arm64/libmmkv.so [arm64-v8a::b18c4565b236796eefe43cb651009b06]
#5 pc 0000000000222244 /apex/com.android.art/lib64/libart.so (art_quick_generic_jni_trampoline+148) [arm64-v8a::5c55b02a7c405b33a3865d31aafbf3f9]
#6 pc 0000000000212b80 /apex/com.android.art/lib64/libart.so (nterp_helper+5648) [arm64-v8a::5c55b02a7c405b33a3865d31aafbf3f9]
#7 pc 00000000002124c4 /apex/com.android.art/lib64/libart.so (nterp_helper+3924) [arm64-v8a::5c55b02a7c405b33a3865d31aafbf3f9]
#8 pc 00000000002124c4 /apex/com.android.art/lib64/libart.so (nterp_helper+3924) [arm64-v8a::5c55b02a7c405b33a3865d31aafbf3f9]
#9 pc 00000000002124c4 /apex/com.android.art/lib64/libart.so (nterp_helper+3924) [arm64-v8a::5c55b02a7c405b33a3865d31aafbf3f9]
#10 pc 00000000002124c4 /apex/com.android.art/lib64/libart.so (nterp_helper+3924) [arm64-v8a::5c55b02a7c405b33a3865d31aafbf3f9]
#11 pc 00000000002132e4 /apex/com.android.art/lib64/libart.so (nterp_helper+7540) [arm64-v8a::5c55b02a7c405b33a3865d31aafbf3f9]
#12 pc 000000000040175c /apex/com.android.art/javalib/arm64/boot.oat [arm64-v8a::41586ef256c8b26d2287aaa827b271c9]

堆栈较多，基本都是读取数据时异常，不一一列举

###原因分析

根本原因与issue相同：#1190 ，crash发生的地方在：decodeData/containsKey——getDataForKey——checkLoadData——partialLoadFromFile——readActualSize访问文件映射内存地址时，内存地址为0空指针异常。

[fzzwork]

Closed as #1190 has fixed this issue.