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| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2018-08-17 15:44:34 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-17 16:20:28 -0700 |
| commit | 6cd00a01f0c1ae6a852b09c59b8dd55cc6c35d1d (patch) | |
| tree | 5cecbb090de3b98d3d2b261783ae96faee8e986d /fs/dcache.c | |
| parent | 480bd56485b77c36e17a411921266c6f06623d98 (diff) | |
| download | lwn-6cd00a01f0c1ae6a852b09c59b8dd55cc6c35d1d.tar.gz lwn-6cd00a01f0c1ae6a852b09c59b8dd55cc6c35d1d.zip | |
fs/dcache.c: fix kmemcheck splat at take_dentry_name_snapshot()
Since only dentry->d_name.len + 1 bytes out of DNAME_INLINE_LEN bytes
are initialized at __d_alloc(), we can't copy the whole size
unconditionally.
WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff8fa27465ac50)
636f6e66696766732e746d70000000000010000000000000020000000188ffff
i i i i i i i i i i i i i u u u u u u u u u u i i i i i u u u u
^
RIP: 0010:take_dentry_name_snapshot+0x28/0x50
RSP: 0018:ffffa83000f5bdf8 EFLAGS: 00010246
RAX: 0000000000000020 RBX: ffff8fa274b20550 RCX: 0000000000000002
RDX: ffffa83000f5be40 RSI: ffff8fa27465ac50 RDI: ffffa83000f5be60
RBP: ffffa83000f5bdf8 R08: ffffa83000f5be48 R09: 0000000000000001
R10: ffff8fa27465ac00 R11: ffff8fa27465acc0 R12: ffff8fa27465ac00
R13: ffff8fa27465acc0 R14: 0000000000000000 R15: 0000000000000000
FS: 00007f79737ac8c0(0000) GS:ffffffff8fc30000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8fa274c0b000 CR3: 0000000134aa7002 CR4: 00000000000606f0
take_dentry_name_snapshot+0x28/0x50
vfs_rename+0x128/0x870
SyS_rename+0x3b2/0x3d0
entry_SYSCALL_64_fastpath+0x1a/0xa4
0xffffffffffffffff
Link: http://lkml.kernel.org/r/201709131912.GBG39012.QMJLOVFSFFOOtH@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/dcache.c')
| -rw-r--r-- | fs/dcache.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 8d2ec4898c2b..2e7e8d85e9b4 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -292,7 +292,8 @@ void take_dentry_name_snapshot(struct name_snapshot *name, struct dentry *dentry spin_unlock(&dentry->d_lock); name->name = p->name; } else { - memcpy(name->inline_name, dentry->d_iname, DNAME_INLINE_LEN); + memcpy(name->inline_name, dentry->d_iname, + dentry->d_name.len + 1); spin_unlock(&dentry->d_lock); name->name = name->inline_name; } |