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authorHe Zhe <zhe.he@windriver.com>2019-08-06 12:41:04 +0300
committerJ. Bruce Fields <bfields@redhat.com>2019-08-16 20:36:55 +0300
commit78e70e780b289ff59ec33a9f9c1fcecaf17a46e1 (patch)
treeda24d7e95af8d4987a193239336ea0a286143a76
parentbebd6997163addc1938db8c61754a23ffdf8ccc4 (diff)
downloadlinux-78e70e780b289ff59ec33a9f9c1fcecaf17a46e1.tar.xz
nfsd4: Fix kernel crash when reading proc file reply_cache_stats
reply_cache_stats uses wrong parameter as seq file private structure and thus causes the following kernel crash when users read /proc/fs/nfsd/reply_cache_stats BUG: kernel NULL pointer dereference, address: 00000000000001f9 PGD 0 P4D 0 Oops: 0000 [#3] SMP PTI CPU: 6 PID: 1502 Comm: cat Tainted: G D 5.3.0-rc3+ #1 Hardware name: Intel Corporation Broadwell Client platform/Basking Ridge, BIOS BDW-E2R1.86C.0118.R01.1503110618 03/11/2015 RIP: 0010:nfsd_reply_cache_stats_show+0x3b/0x2d0 Code: 41 54 49 89 f4 48 89 fe 48 c7 c7 b3 10 33 88 53 bb e8 03 00 00 e8 88 82 d1 ff bf 58 89 41 00 e8 eb c5 85 00 48 83 eb 01 75 f0 <41> 8b 94 24 f8 01 00 00 48 c7 c6 be 10 33 88 4c 89 ef bb e8 03 00 RSP: 0018:ffffaa520106fe08 EFLAGS: 00010246 RAX: 000000cfe1a77123 RBX: 0000000000000000 RCX: 0000000000291b46 RDX: 000000cf00000000 RSI: 0000000000000006 RDI: 0000000000291b28 RBP: ffffaa520106fe20 R08: 0000000000000006 R09: 000000cfe17e55dd R10: ffffa424e47c0000 R11: 000000000000030b R12: 0000000000000001 R13: ffffa424e5697000 R14: 0000000000000001 R15: ffffa424e5697000 FS: 00007f805735f580(0000) GS:ffffa424f8f80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000001f9 CR3: 00000000655ce005 CR4: 00000000003606e0 Call Trace: seq_read+0x194/0x3e0 __vfs_read+0x1b/0x40 vfs_read+0x95/0x140 ksys_read+0x61/0xe0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x4d/0x120 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f805728b861 Code: fe ff ff 50 48 8d 3d 86 b4 09 00 e8 79 e0 01 00 66 0f 1f 84 00 00 00 00 00 48 8d 05 d9 19 0d 00 8b 00 85 c0 75 13 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 57 c3 66 0f 1f 44 00 00 48 83 ec 28 48 89 54 RSP: 002b:00007ffea1ce3c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007f805728b861 RDX: 0000000000020000 RSI: 00007f8057183000 RDI: 0000000000000003 RBP: 00007f8057183000 R08: 00007f8057182010 R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 0000559a60e8ff10 R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000 Modules linked in: CR2: 00000000000001f9 ---[ end trace 01613595153f0cba ]--- RIP: 0010:nfsd_reply_cache_stats_show+0x3b/0x2d0 Code: 41 54 49 89 f4 48 89 fe 48 c7 c7 b3 10 33 88 53 bb e8 03 00 00 e8 88 82 d1 ff bf 58 89 41 00 e8 eb c5 85 00 48 83 eb 01 75 f0 <41> 8b 94 24 f8 01 00 00 48 c7 c6 be 10 33 88 4c 89 ef bb e8 03 00 RSP: 0018:ffffaa52004b3e08 EFLAGS: 00010246 RAX: 0000002bab45a7c6 RBX: 0000000000000000 RCX: 0000000000291b4c RDX: 0000002b00000000 RSI: 0000000000000004 RDI: 0000000000291b28 RBP: ffffaa52004b3e20 R08: 0000000000000004 R09: 0000002bab1c8c7a R10: ffffa424e5500000 R11: 00000000000002a9 R12: 0000000000000001 R13: ffffa424e4475000 R14: 0000000000000001 R15: ffffa424e4475000 FS: 00007f805735f580(0000) GS:ffffa424f8f80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000001f9 CR3: 00000000655ce005 CR4: 00000000003606e0 Killed Fixes: 3ba75830ce17 ("nfsd4: drc containerization") Signed-off-by: He Zhe <zhe.he@windriver.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
-rw-r--r--fs/nfsd/nfscache.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 26ad75ae2be0..96352ab7bd81 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -571,7 +571,7 @@ nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *data)
*/
static int nfsd_reply_cache_stats_show(struct seq_file *m, void *v)
{
- struct nfsd_net *nn = v;
+ struct nfsd_net *nn = m->private;
seq_printf(m, "max entries: %u\n", nn->max_drc_entries);
seq_printf(m, "num entries: %u\n",