C-blosc2 before 2.9.3 was discovered to contain a NULL pointer dereference via the function zfp_prec_decompress at zfp/blosc2-zfp.c.
**Describe the bug**
Null Pointer Dereferencing at line **391** in [plugins/codecs/zfp/blosc2-zfp.c](https://github.com/Blosc/c-blosc2/blob/86fc0f66aa6dd079dbf79d775dc9dc1462830ffd/plugins/codecs/zfp/blosc2-zfp.c#LL391C29-L391C29). This is caused due to using a pointer to a chunk which does not exist. This bug is in the function `zfp_prec_decompress`.

**To Reproduce**
Run the fuzzing harness `fuzz_decompress_chunk` with the attached input (in Zip File)
[null-ptr-1.zip](https://github.com/Blosc/c-blosc2/files/11807475/null-ptr-1.zip)

**Expected behavior**
Check whether the chunk is a correct pointer at line 390.

**Logs**
If applicable, add logs to help explain your problem.

**System information:**
 - OS: Ubuntu 20.04
 - Compiler: clang-11
 - Version: Latest commit on `main` branch

**Additional context**
This bug has been found by fuzzing.


Null Pointer Dereferencing bug in plugins/codecs/zfp/blosc2-zfp.c
This is a GitHub Issue
repo:c-blosc2
owner:Blosc
Title : Null Pointer Dereferencing bug in plugins/codecs/zfp/blosc2-zfp.c
Issue date:

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**Describe the bug**
Null Pointer Dereferencing at line **391** in [plugins/codecs/zfp/blosc2-zfp.c](https://github.com/Blosc/c-blosc2/blob/86fc0f66aa6dd079dbf79d775dc9dc1462830ffd/plugins/codecs/zfp/blosc2-zfp.c#LL391C29-L391C29). This is caused due to using a pointer to a chunk which does not exist. This bug is in the function `zfp_prec_decompress`.

**To Reproduce**
Run the fuzzing harness `fuzz_decompress_chunk` with the attached input (in Zip File)
[null-ptr-1.zip](https://github.com/Blosc/c-blosc2/files/11807475/null-ptr-1.zip)

**Expected behavior**
Check whether the chunk is a correct pointer at line 390.

**Logs**
If applicable, add logs to help explain your problem.

**System information:**
 - OS: Ubuntu 20.04
 - Compiler: clang-11
 - Version: Latest commit on `main` branch

**Additional context**
This bug has been found by fuzzing.


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A null pointer dereferencing vulnerability in the `zfp_prec_decompress` function of c-blosc2 can lead to application crashes or undefined behavior when processing invalid input. This occurs at line 391 in `blosc2-zfp.c`, where the code attempts to access a chunk pointer that may not be valid, potentially allowing an attacker to exploit this flaw through crafted input data.