| Message ID | 1638322402-54754-1-git-send-email-cuibixuan@linux.alibaba.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | [-next,v2] bpf: Add oversize check before call kvmalloc() | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
| bpf/vmtest-bpf-next-PR | success | PR summary |
| bpf/vmtest-bpf-next | success | VM_Test |
On Wed, Dec 01, 2021 at 09:33:22AM +0800, Bixuan Cui wrote: > Commit 7661809d493b ("mm: don't allow oversized kvmalloc() calls") add > the oversize check. When the allocation is larger than what kvmalloc() > supports, the following warning triggered: > > WARNING: CPU: 1 PID: 372 at mm/util.c:597 kvmalloc_node+0x111/0x120 > mm/util.c:597 > Modules linked in: > CPU: 1 PID: 372 Comm: syz-executor.4 Not tainted 5.15.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:kvmalloc_node+0x111/0x120 mm/util.c:597 > Code: 01 00 00 00 4c 89 e7 e8 7d f7 0c 00 49 89 c5 e9 69 ff ff ff e8 60 > 20 d1 ff 41 89 ed 41 81 cd 00 20 01 00 eb 95 e8 4f 20 d1 ff <0f> 0b e9 > 4c ff ff ff 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 e8 36 > RSP: 0018:ffffc90002bf7c98 EFLAGS: 00010216 > RAX: 00000000000000ec RBX: 1ffff9200057ef9f RCX: ffffc9000ac63000 > RDX: 0000000000040000 RSI: ffffffff81a6a621 RDI: 0000000000000003 > RBP: 0000000000102cc0 R08: 000000007fffffff R09: 00000000ffffffff > R10: ffffffff81a6a5de R11: 0000000000000000 R12: 00000000ffff9aaa > R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000 > FS: 00007f05f2573700(0000) GS:ffff8880b9d00000(0000) > knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000001b2f424000 CR3: 0000000027d2c000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <TASK> > kvmalloc include/linux/slab.h:741 [inline] > map_lookup_elem kernel/bpf/syscall.c:1090 [inline] > __sys_bpf+0x3a5b/0x5f00 kernel/bpf/syscall.c:4603 > __do_sys_bpf kernel/bpf/syscall.c:4722 [inline] > __se_sys_bpf kernel/bpf/syscall.c:4720 [inline] > __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4720 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > > The type of 'value_size' is u32, its value may exceed INT_MAX. > > Reported-by: syzbot+cecf5b7071a0dfb76530@syzkaller.appspotmail.com > Signed-off-by: Bixuan Cui <cuibixuan@linux.alibaba.com> > --- > Changes in v2: > * Change the err from -EINVAL to -E2BIG; > * Change "goto err_put" to "goto free_key"; Please fix kvmalloc instead. https://lore.kernel.org/all/YadOjJXMTjP85MQx@unreal diff --git a/mm/util.c b/mm/util.c index 741ba32a43ac..3749f4a16ab9 100644 --- a/mm/util.c +++ b/mm/util.c @@ -594,7 +594,7 @@ void *kvmalloc_node(size_t size, gfp_t flags, int node) return ret; /* Don't even allow crazy sizes */ - if (WARN_ON_ONCE(size > INT_MAX)) + if (size > INT_MAX) return NULL; return __vmalloc_node(size, 1, flags, node, > > kernel/bpf/syscall.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c > index 1033ee8..30aabdd 100644 > --- a/kernel/bpf/syscall.c > +++ b/kernel/bpf/syscall.c > @@ -1094,6 +1094,10 @@ static int map_lookup_elem(union bpf_attr *attr) > } > > value_size = bpf_map_value_size(map); > + if (value_size > INT_MAX) { > + err = -E2BIG; > + goto free_key; > + } > > err = -ENOMEM; > value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN); > -- > 1.8.3.1 >
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 1033ee8..30aabdd 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1094,6 +1094,10 @@ static int map_lookup_elem(union bpf_attr *attr) } value_size = bpf_map_value_size(map); + if (value_size > INT_MAX) { + err = -E2BIG; + goto free_key; + } err = -ENOMEM; value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
Commit 7661809d493b ("mm: don't allow oversized kvmalloc() calls") add the oversize check. When the allocation is larger than what kvmalloc() supports, the following warning triggered: WARNING: CPU: 1 PID: 372 at mm/util.c:597 kvmalloc_node+0x111/0x120 mm/util.c:597 Modules linked in: CPU: 1 PID: 372 Comm: syz-executor.4 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvmalloc_node+0x111/0x120 mm/util.c:597 Code: 01 00 00 00 4c 89 e7 e8 7d f7 0c 00 49 89 c5 e9 69 ff ff ff e8 60 20 d1 ff 41 89 ed 41 81 cd 00 20 01 00 eb 95 e8 4f 20 d1 ff <0f> 0b e9 4c ff ff ff 0f 1f 84 00 00 00 00 00 55 48 89 fd 53 e8 36 RSP: 0018:ffffc90002bf7c98 EFLAGS: 00010216 RAX: 00000000000000ec RBX: 1ffff9200057ef9f RCX: ffffc9000ac63000 RDX: 0000000000040000 RSI: ffffffff81a6a621 RDI: 0000000000000003 RBP: 0000000000102cc0 R08: 000000007fffffff R09: 00000000ffffffff R10: ffffffff81a6a5de R11: 0000000000000000 R12: 00000000ffff9aaa R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000 FS: 00007f05f2573700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f424000 CR3: 0000000027d2c000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> kvmalloc include/linux/slab.h:741 [inline] map_lookup_elem kernel/bpf/syscall.c:1090 [inline] __sys_bpf+0x3a5b/0x5f00 kernel/bpf/syscall.c:4603 __do_sys_bpf kernel/bpf/syscall.c:4722 [inline] __se_sys_bpf kernel/bpf/syscall.c:4720 [inline] __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:4720 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae The type of 'value_size' is u32, its value may exceed INT_MAX. Reported-by: syzbot+cecf5b7071a0dfb76530@syzkaller.appspotmail.com Signed-off-by: Bixuan Cui <cuibixuan@linux.alibaba.com> --- Changes in v2: * Change the err from -EINVAL to -E2BIG; * Change "goto err_put" to "goto free_key"; kernel/bpf/syscall.c | 4 ++++ 1 file changed, 4 insertions(+)