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| author | Vegard Nossum <vegard.nossum@oracle.com> | 2015-12-16 21:59:56 +0100 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-02-09 22:56:34 -0500 |
| commit | 1b23fd3a516c375736a5992cbced55a1e8e9285b (patch) | |
| tree | 55f6f83a0a7cccac532ecdce38b1466f5cf56a08 /fs | |
| parent | ba6ef126d34a2ae6e76baf0f671ba770f4e51fc0 (diff) | |
| download | lwn-1b23fd3a516c375736a5992cbced55a1e8e9285b.tar.gz lwn-1b23fd3a516c375736a5992cbced55a1e8e9285b.zip | |
uml: fix hostfs mknod()
[ Upstream commit 9f2dfda2f2f1c6181c3732c16b85c59ab2d195e0 ]
An inverted return value check in hostfs_mknod() caused the function
to return success after handling it as an error (and cleaning up).
It resulted in the following segfault when trying to bind() a named
unix socket:
Pid: 198, comm: a.out Not tainted 4.4.0-rc4
RIP: 0033:[<0000000061077df6>]
RSP: 00000000daae5d60 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000006092a460 RCX: 00000000dfc54208
RDX: 0000000061073ef1 RSI: 0000000000000070 RDI: 00000000e027d600
RBP: 00000000daae5de0 R08: 00000000da980ac0 R09: 0000000000000000
R10: 0000000000000003 R11: 00007fb1ae08f72a R12: 0000000000000000
R13: 000000006092a460 R14: 00000000daaa97c0 R15: 00000000daaa9a88
Kernel panic - not syncing: Kernel mode fault at addr 0x40, ip 0x61077df6
CPU: 0 PID: 198 Comm: a.out Not tainted 4.4.0-rc4 #1
Stack:
e027d620 dfc54208 0000006f da981398
61bee000 0000c1ed daae5de0 0000006e
e027d620 dfcd4208 00000005 6092a460
Call Trace:
[<60dedc67>] SyS_bind+0xf7/0x110
[<600587be>] handle_syscall+0x7e/0x80
[<60066ad7>] userspace+0x3e7/0x4e0
[<6006321f>] ? save_registers+0x1f/0x40
[<6006c88e>] ? arch_prctl+0x1be/0x1f0
[<60054985>] fork_handler+0x85/0x90
Let's also get rid of the "cosmic ray protection" while we're at it.
Fixes: e9193059b1b3 "hostfs: fix races in dentry_name() and inode_name()"
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/hostfs/hostfs_kern.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c index fd62cae0fdcb..6e4a3f1b9ce2 100644 --- a/fs/hostfs/hostfs_kern.c +++ b/fs/hostfs/hostfs_kern.c @@ -720,15 +720,13 @@ static int hostfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, init_special_inode(inode, mode, dev); err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); - if (!err) + if (err) goto out_free; err = read_name(inode, name); __putname(name); if (err) goto out_put; - if (err) - goto out_put; d_instantiate(dentry, inode); return 0; |