diff options
| author | David Disseldorp <ddiss@suse.de> | 2021-04-23 01:14:03 +0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2021-04-26 00:28:24 +0300 |
| commit | 315db9a05b7a56810728589baa930864107e4634 (patch) | |
| tree | c115e12a227a2b13a76d2bbbe7836cb45d74efa8 /fs | |
| parent | ad7567bc65afe0ef0d1b853aa4d54c44d09223dc (diff) | |
| download | linux-315db9a05b7a56810728589baa930864107e4634.tar.xz | |
cifs: fix leak in cifs_smb3_do_mount() ctx
cifs_smb3_do_mount() calls smb3_fs_context_dup() and then
cifs_setup_volume_info(). The latter's subsequent smb3_parse_devname()
call overwrites the cifs_sb->ctx->UNC string already dup'ed by
smb3_fs_context_dup(), resulting in a leak. E.g.
unreferenced object 0xffff888002980420 (size 32):
comm "mount", pid 160, jiffies 4294892541 (age 30.416s)
hex dump (first 32 bytes):
5c 5c 31 39 32 2e 31 36 38 2e 31 37 34 2e 31 30 \\192.168.174.10
34 5c 72 61 70 69 64 6f 2d 73 68 61 72 65 00 00 4\rapido-share..
backtrace:
[<00000000069e12f6>] kstrdup+0x28/0x50
[<00000000b61f4032>] smb3_fs_context_dup+0x127/0x1d0 [cifs]
[<00000000c6e3e3bf>] cifs_smb3_do_mount+0x77/0x660 [cifs]
[<0000000063467a6b>] smb3_get_tree+0xdf/0x220 [cifs]
[<00000000716f731e>] vfs_get_tree+0x1b/0x90
[<00000000491d3892>] path_mount+0x62a/0x910
[<0000000046b2e774>] do_mount+0x50/0x70
[<00000000ca7b64dd>] __x64_sys_mount+0x81/0xd0
[<00000000b5122496>] do_syscall_64+0x33/0x40
[<000000002dd397af>] entry_SYSCALL_64_after_hwframe+0x44/0xae
This change is a bandaid until the cifs_setup_volume_info() TODO and
error handling issues are resolved.
Signed-off-by: David Disseldorp <ddiss@suse.de>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
CC: <stable@vger.kernel.org> # v5.11+
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/cifs/cifsfs.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 4257f841ec4e..39f4889a036b 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -855,6 +855,12 @@ cifs_smb3_do_mount(struct file_system_type *fs_type, goto out; } + /* cifs_setup_volume_info->smb3_parse_devname() redups UNC & prepath */ + kfree(cifs_sb->ctx->UNC); + cifs_sb->ctx->UNC = NULL; + kfree(cifs_sb->ctx->prepath); + cifs_sb->ctx->prepath = NULL; + rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, old_ctx->UNC); if (rc) { root = ERR_PTR(rc); |