padata: use integer wrap around to prevent deadlock on seq_nr overflow

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: padata: use integer wrap around to prevent deadlock on seq_nr overflow When submitting more than 2^32 padata objects to padata_do_serial, the current sorting implementation incorrectly sorts padata objects with overflowed seq_nr, causing them to be placed before existing objects in the reorder list. This leads to a deadlock in the serialization process as padata_find_next cannot match padata->seq_nr and pd->processed because the padata instance with overflowed seq_nr will be selected next. To fix this, we use an unsigned integer wrap around to correctly sort padata objects in scenarios with integer overflow.

References

• https://git.kernel.org/stable/c/46c4079460f4dcaf445860679558eedef4e1bc91
• https://git.kernel.org/stable/c/72164d5b648951684b1a593996b37a6083c61d7d
• https://git.kernel.org/stable/c/ab205e1c3846326f162180e56825b4ba38ce9c30
• https://git.kernel.org/stable/c/1b8cf11b3ca593a8802a51802cd0c28c38501428
• https://git.kernel.org/stable/c/9e279e6c1f012b82628b89e1b9c65dbefa8ca25a
• https://git.kernel.org/stable/c/1bd712de96ad7167fe0d608e706cd60587579f16
• https://git.kernel.org/stable/c/9a22b2812393d93d84358a760c347c21939029a6