Affected: Linux

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

crypto: af_alg - get rid of alg_memory_allocated

alg_memory_allocated does not seem to be really used.

alg_proto does have a .memory_allocated field, but no corresponding .sysctl_mem.

This means sk_has_account() returns true, but all sk_prot_mem_limits() users will trigger a NULL dereference [1].

THis was not a problem until SO_RESERVE_MEM addition.

general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 1 PID: 3591 Comm: syz-executor153 Not tainted 5.17.0-rc3-syzkaller-00316-gb81b1829e7e3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:sk_prot_mem_limits include/net/sock.h:1523 [inline] RIP: 0010:sock_reserve_memory+0x1d7/0x330 net/core/sock.c:1000 Code: 08 00 74 08 48 89 ef e8 27 20 bb f9 4c 03 7c 24 10 48 8b 6d 00 48 83 c5 08 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 ef e8 fb 1f bb f9 48 8b 6d 00 4c 89 ff 48 RSP: 0018:ffffc90001f1fb68 EFLAGS: 00010202 RAX: 0000000000000001 RBX: ffff88814aabc000 RCX: dffffc0000000000 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff90e18120 RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff21c3025 R10: fffffbfff21c3025 R11: 0000000000000000 R12: ffffffff8d109840 R13: 0000000000001002 R14: 0000000000000001 R15: 0000000000000001 FS: 0000…