Re: [PATCH] x86/pm: Fix false positive kmemleak report in msr_build_context().

On 3/14/24 07:26, Anton Altaparmakov wrote:

/* image of the saved processor state */ struct saved_context {

• /*

• * On x86_32, all segment registers except gs are saved at kernel
  

• * entry in pt_regs.
  

• */
  

• u16 gs; unsigned long cr0, cr2, cr3, cr4; u64 misc_enable; struct saved_msrs saved_msrs;

@@ -27,6 +22,11 @@ struct saved_context { unsigned long tr; unsigned long safety; unsigned long return_address;

• /*

• * On x86_32, all segment registers except gs are saved at kernel
  

• * entry in pt_regs.
  

• */
  

• u16 gs; bool misc_enable_saved;

} __attribute__((packed));

Isn't this just kinda poking at the symptoms? This seems to be basically the exact same bug as b0b592cf08, just with a different source of unaligned structure members.

There's nothing to keep folks from reintroducing these kinds of issues and evidently no way to detect when they happen without lengthy reproducers.