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| author | Will Deacon <will.deacon@arm.com> | 2013-08-21 21:24:47 +0400 |
|---|---|---|
| committer | Eric Van Hensbergen <ericvh@gmail.com> | 2013-08-26 19:28:46 +0400 |
| commit | 50192abe02929586111fb33f216060a9341875f1 (patch) | |
| tree | c766629c78fc8410eb452e018b0ba4b629141a3e /include/net/9p | |
| parent | e0d6cb9cd3a3ac8a3b8e5b22b83c4f8619786f22 (diff) | |
| download | linux-50192abe02929586111fb33f216060a9341875f1.tar.xz | |
fs/9p: avoid accessing utsname after namespace has been torn down
During trinity fuzzing in a kvmtool guest, I stumbled across the
following:
Unable to handle kernel NULL pointer dereference at virtual address 00000004
PC is at v9fs_file_do_lock+0xc8/0x1a0
LR is at v9fs_file_do_lock+0x48/0x1a0
[<c01e2ed0>] (v9fs_file_do_lock+0xc8/0x1a0) from [<c0119154>] (locks_remove_flock+0x8c/0x124)
[<c0119154>] (locks_remove_flock+0x8c/0x124) from [<c00d9bf0>] (__fput+0x58/0x1e4)
[<c00d9bf0>] (__fput+0x58/0x1e4) from [<c0044340>] (task_work_run+0xac/0xe8)
[<c0044340>] (task_work_run+0xac/0xe8) from [<c002e36c>] (do_exit+0x6bc/0x8d8)
[<c002e36c>] (do_exit+0x6bc/0x8d8) from [<c002e674>] (do_group_exit+0x3c/0xb0)
[<c002e674>] (do_group_exit+0x3c/0xb0) from [<c002e6f8>] (__wake_up_parent+0x0/0x18)
I believe this is due to an attempt to access utsname()->nodename, after
exit_task_namespaces() has been called, leaving current->nsproxy->uts_ns
as NULL and causing the above dereference.
A similar issue was fixed for lockd in 9a1b6bf818e7 ("LOCKD: Don't call
utsname()->nodename from nlmclnt_setlockargs"), so this patch attempts
something similar for 9pfs.
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Diffstat (limited to 'include/net/9p')
| -rw-r--r-- | include/net/9p/client.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/net/9p/client.h b/include/net/9p/client.h index 4c7c01a73911..c38a005bd0cf 100644 --- a/include/net/9p/client.h +++ b/include/net/9p/client.h @@ -26,6 +26,8 @@ #ifndef NET_9P_CLIENT_H #define NET_9P_CLIENT_H +#include <linux/utsname.h> + /* Number of requests per row */ #define P9_ROW_MAXTAG 255 @@ -134,6 +136,7 @@ struct p9_req_t { * @tagpool - transaction id accounting for session * @reqs - 2D array of requests * @max_tag - current maximum tag id allocated + * @name - node name used as client id * * The client structure is used to keep track of various per-client * state that has been instantiated. @@ -164,6 +167,8 @@ struct p9_client { struct p9_idpool *tagpool; struct p9_req_t *reqs[P9_ROW_MAXTAG]; int max_tag; + + char name[__NEW_UTS_LEN + 1]; }; /** |