In the Linux kernel, the following vulnerability has been resolved: f2fs: quota: fix loop condition at f2fs_quota_sync() cnt should be passed to sb_has_quota_active() instead of type to check active quota properly. Moreover, when the type is -1, the compiler with enough inline knowledge can discard sb_has_quota_active() check altogether, causing a NULL pointer dereference at the following inode_lock(dqopt->files[cnt]): [ 2.796010] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a0 [ 2.796024] Mem abort info: [ 2.796025] ESR = 0x96000005 [ 2.796028] EC = 0x25: DABT (current EL), IL = 32 bits [ 2.796029] SET = 0, FnV = 0 [ 2.796031] EA = 0, S1PTW = 0 [ 2.796032] Data abort info: [ 2.796034] ISV = 0, ISS = 0x00000005 [