CVE-2023-53860 in Linux
الملخص
بحسب VulDB • 05/06/2026
Based on the stack trace provided, here is the analysis of where the issue is occurring:
### 1. **The Crash Location (RIP)** The instruction pointer (`RIP`) is at: ``` RIP: 0033:0x7f5af41ad806 ``` This is **user-space code**, not kernel code. The address `0x7f5af41ad806` is in the memory-mapped region of a shared library (likely `libc.so.6` or a similar C library), as indicated by the `0x7f...` prefix and the `Code:` dump showing standard x86-64 instructions.
### 2. **The System Call** The system call number is: ``` ORIG_RAX: 0000000000000147 ``` `0x147` (hex) = **327** (decimal). On x86-64 Linux, syscall 327 is **`preadv2`**.
The stack confirms this: ``` __x64_sys_preadv2+0xef/0x150 do_preadv+0x1b3/0x260 vfs_readv+0x12d/0x1a0 do_iter_read+0x31b/0x880 blkdev_read_iter+0x2a4/0x530 blkdev_direct_IO.part.0+0x84a/0x1810 ```
### 3. **The Kernel Path** The kernel is handling a **direct I/O read** on a **block device** (`blkdev_direct_IO`). The path is: 1. User calls `preadv2` (syscall). 2. Kernel enters `vfs_readv` → `do_iter_read`. 3. Since it’s a block device and likely using direct I/O (O_DIRECT), it goes to `blkdev_read_iter`. 4. This triggers `blkdev_direct_IO`, which is where the crash occurs.
### 4. **The Actual Crash Point** The crash happens **inside user-space**, but the **kernel is in the middle of servicing the syscall**. This typically means: - The kernel crashed **before** returning to user-space, **OR** - The kernel returned an error, and the **user-space library** (e.g., `libc`) crashed while handling the error.
However, the `RIP` is in user-space, and the stack shows the kernel is still active (`<TASK>`). This is a **classic symptom of a kernel panic/oops that corrupted user-space memory or caused a signal**, but the `RIP` shown is where the **user-space process was executing** when the signal was delivered or when the crash was detected.
But wait: **The stack trace is from the kernel perspective.** The `RIP` shown is the **user-space instruction pointer** at the time the kernel was interrupted or when the crash occurred. If the kernel crashed, the `RIP` would be in kernel space. Since `RIP` is in user space, this suggests:
### **Most Likely Scenario: User-Space Crash Triggered by Kernel** The kernel is handling a `preadv2` on a block device. The crash `RIP` is in user-space. This often happens when: 1. The kernel **segfaults** or **oopses** during `blkdev_direct_IO`, but the crash dump captures the user-space context. 2. **More likely:** The **user-space application** crashed (e.g., segfault) **while** the kernel was still processing the syscall. The kernel stack shows it was in `blkdev_direct_IO`.
### **Key Clue: `blkdev_direct_IO`** The function `blkdev_direct_IO` is where direct I/O is performed. If this function has a bug (e.g., null pointer dereference, invalid memory access), it will cause a kernel oops. However, the `RIP` is in user-space.
### **Conclusion** - **The crash is in user-space** (`0x7f5af41ad806`), likely in `libc` or the application itself. - **The kernel was servicing a `preadv2` syscall** on a block device using direct I/O. - **Possible causes:** 1. **User-space bug:** The application passed invalid pointers to `preadv2`, causing a segfault in user-space while the kernel was processing it. 2. **Kernel bug:** The kernel crashed in `blkdev_direct_IO`, but the crash dump shows the user-space RIP because the signal was delivered to the user-space process
VulDB is the best source for vulnerability data and more expert information about this specific topic.