2022-02-14 15:07:19

by Eric Dumazet

[permalink] [raw]
Subject: [PATCH] crypto: af_alg - get rid of alg_memory_allocated

From: Eric Dumazet <[email protected]>

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: 0000555556e08300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc74416f130 CR3: 0000000073d9e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
sock_setsockopt+0x14a9/0x3a30 net/core/sock.c:1446
__sys_setsockopt+0x5af/0x980 net/socket.c:2176
__do_sys_setsockopt net/socket.c:2191 [inline]
__se_sys_setsockopt net/socket.c:2188 [inline]
__x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2188
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fc7440fddc9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe98f07968 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fc7440fddc9
RDX: 0000000000000049 RSI: 0000000000000001 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000004 R09: 00007ffe98f07990
R10: 0000000020000000 R11: 0000000000000246 R12: 00007ffe98f0798c
R13: 00007ffe98f079a0 R14: 00007ffe98f079e0 R15: 0000000000000000
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
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: 0000555556e08300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc74416f130 CR3: 0000000073d9e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000

Fixes: 2bb2f5fb21b0 ("net: add new socket option SO_RESERVE_MEM")
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Wei Wang <[email protected]>
Reported-by: syzbot <[email protected]>
---
crypto/af_alg.c | 3 ---
1 file changed, 3 deletions(-)

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index e1ea18536a5f085c816c88bb28da029a5f3a1d3e..c8289b7a85baaa0a83fefcfc0928ea67d522f98c 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -25,12 +25,9 @@ struct alg_type_list {
struct list_head list;
};

-static atomic_long_t alg_memory_allocated;
-
static struct proto alg_proto = {
.name = "ALG",
.owner = THIS_MODULE,
- .memory_allocated = &alg_memory_allocated,
.obj_size = sizeof(struct alg_sock),
};

--
2.35.1.265.g69c8d7142f-goog


2022-02-15 15:31:01

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH] crypto: af_alg - get rid of alg_memory_allocated

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <[email protected]>:

On Sun, 13 Feb 2022 11:06:07 -0800 you wrote:
> From: Eric Dumazet <[email protected]>
>
> alg_memory_allocated does not seem to be really used.
>
> alg_proto does have a .memory_allocated field, but no
> corresponding .sysctl_mem.
>
> [...]

Here is the summary with links:
- crypto: af_alg - get rid of alg_memory_allocated
https://git.kernel.org/netdev/net/c/25206111512d

You are awesome, thank you!
--
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