CVE-2024-42315

In the Linux kernel, the following vulnerability has been resolved:

exfat: fix potential deadlock on _exfatgetdentryset

When accessing a file with more entries than ESMAXENTRY_NUM, the bh-array is allocated in _exfatgetentryset. The problem is that the bh-array is allocated with GFPKERNEL. It does not make sense. In the following cases, a deadlock for sbi->slock between the two processes may occur.

   CPU0                CPU1
   ----                ----

kswapd balancepgdat lock(fsreclaim) exfatiterate lock(&sbi->slock) exfatreaddir exfatgetuninamefromextentry exfatgetdentry_set __exfatgetdentryset kmallocarray ... lock(fsreclaim) ... evict exfatevictinode lock(&sbi->slock)

To fix this, let's allocate bh-array with GFP_NOFS.