Skip to content

Commit

Permalink
cifs: use cifsInodeInfo->open_file_lock while iterating to avoid a panic
Browse files Browse the repository at this point in the history 
Commit 487317c ("cifs: add spinlock for the openFileList to
cifsInodeInfo") added cifsInodeInfo->open_file_lock spin_lock to protect
the openFileList, but missed a few places where cifs_inode->openFileList
was enumerated.  Change these remaining tcon->open_file_lock to
cifsInodeInfo->open_file_lock to avoid panic in is_size_safe_to_change.

[17313.245641] RIP: 0010:is_size_safe_to_change+0x57/0xb0 [cifs]
[17313.245645] Code: 68 40 48 89 ef e8 19 67 b7 f1 48 8b 43 40 48 8d 4b 40 48 8d 50 f0 48 39 c1 75 0f eb 47 48 8b 42 10 48 8d 50 f0 48 39 c1 74 3a <8b> 80 88 00 00 00 83 c0 01 a8 02 74 e6 48 89 ef c6 07 00 0f 1f 40
[17313.245649] RSP: 0018:ffff94ae1baefa30 EFLAGS: 00010202
[17313.245654] RAX: dead000000000100 RBX: ffff88dc72243300 RCX: ffff88dc72243340
[17313.245657] RDX: dead0000000000f0 RSI: 00000000098f7940 RDI: ffff88dd3102f040
[17313.245659] RBP: ffff88dd3102f040 R08: 0000000000000000 R09: ffff94ae1baefc40
[17313.245661] R10: ffffcdc8bb1c4e80 R11: ffffcdc8b50adb08 R12: 00000000098f7940
[17313.245663] R13: ffff88dc72243300 R14: ffff88dbc8f19600 R15: ffff88dc72243428
[17313.245667] FS:  00007fb145485700(0000) GS:ffff88dd3e000000(0000) knlGS:0000000000000000
[17313.245670] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[17313.245672] CR2: 0000026bb46c6000 CR3: 0000004edb110003 CR4: 00000000007606e0
[17313.245753] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[17313.245756] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[17313.245759] PKRU: 55555554
[17313.245761] Call Trace:
[17313.245803]  cifs_fattr_to_inode+0x16b/0x580 [cifs]
[17313.245838]  cifs_get_inode_info+0x35c/0xa60 [cifs]
[17313.245852]  ? kmem_cache_alloc_trace+0x151/0x1d0
[17313.245885]  cifs_open+0x38f/0x990 [cifs]
[17313.245921]  ? cifs_revalidate_dentry_attr+0x3e/0x350 [cifs]
[17313.245953]  ? cifsFileInfo_get+0x30/0x30 [cifs]
[17313.245960]  ? do_dentry_open+0x132/0x330
[17313.245963]  do_dentry_open+0x132/0x330
[17313.245969]  path_openat+0x573/0x14d0
[17313.245974]  do_filp_open+0x93/0x100
[17313.245979]  ? __check_object_size+0xa3/0x181
[17313.245986]  ? audit_alloc_name+0x7e/0xd0
[17313.245992]  do_sys_open+0x184/0x220
[17313.245999]  do_syscall_64+0x5b/0x1b0

Fixes: 487317c ("cifs: add spinlock for the openFileList to cifsInodeInfo")

CC: Stable <[email protected]>
Signed-off-by: Dave Wysochanski <[email protected]>
Reviewed-by: Ronnie Sahlberg <[email protected]>
Signed-off-by: Steve French <[email protected]>
  • Loading branch information
@DaveWysochanskiRH
DaveWysochanskiRH authored and Steve French committed Oct 7, 2019
1 parent dd19c10 commit cb24881
Showing 1 changed file with 11 additions and 16 deletions.
27 changes: 11 additions & 16 deletions fs/cifs/file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1840,13 +1840,12 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
{
struct cifsFileInfo *open_file = NULL;
struct cifs_sb_info *cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);

/* only filter by fsuid on multiuser mounts */
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
fsuid_only = false;

spin_lock(&tcon->open_file_lock);
spin_lock(&cifs_inode->open_file_lock);
/* we could simply get the first_list_entry since write-only entries
are always at the end of the list but since the first entry might
have a close pending, we go through the whole list */
Expand All @@ -1858,15 +1857,15 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
/* found a good file */
/* lock it so it will not be closed on us */
cifsFileInfo_get(open_file);
spin_unlock(&tcon->open_file_lock);
spin_unlock(&cifs_inode->open_file_lock);
return open_file;
} /* else might as well continue, and look for
another, or simply have the caller reopen it
again rather than trying to fix this handle */
} else /* write only file */
break; /* write only files are last so must be done */
}
spin_unlock(&tcon->open_file_lock);
spin_unlock(&cifs_inode->open_file_lock);
return NULL;
}

Expand All @@ -1877,7 +1876,6 @@ cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only,
{
struct cifsFileInfo *open_file, *inv_file = NULL;
struct cifs_sb_info *cifs_sb;
struct cifs_tcon *tcon;
bool any_available = false;
int rc = -EBADF;
unsigned int refind = 0;
Expand All @@ -1897,16 +1895,15 @@ cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only,
}

cifs_sb = CIFS_SB(cifs_inode->vfs_inode.i_sb);
tcon = cifs_sb_master_tcon(cifs_sb);

/* only filter by fsuid on multiuser mounts */
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
fsuid_only = false;

spin_lock(&tcon->open_file_lock);
spin_lock(&cifs_inode->open_file_lock);
refind_writable:
if (refind > MAX_REOPEN_ATT) {
spin_unlock(&tcon->open_file_lock);
spin_unlock(&cifs_inode->open_file_lock);
return rc;
}
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
Expand All @@ -1918,7 +1915,7 @@ cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only,
if (!open_file->invalidHandle) {
/* found a good writable file */
cifsFileInfo_get(open_file);
spin_unlock(&tcon->open_file_lock);
spin_unlock(&cifs_inode->open_file_lock);
*ret_file = open_file;
return 0;
} else {
Expand All @@ -1938,7 +1935,7 @@ cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only,
cifsFileInfo_get(inv_file);
}

spin_unlock(&tcon->open_file_lock);
spin_unlock(&cifs_inode->open_file_lock);

if (inv_file) {
rc = cifs_reopen_file(inv_file, false);
Expand All @@ -1953,7 +1950,7 @@ cifs_get_writable_file(struct cifsInodeInfo *cifs_inode, bool fsuid_only,
cifsFileInfo_put(inv_file);
++refind;
inv_file = NULL;
spin_lock(&tcon->open_file_lock);
spin_lock(&cifs_inode->open_file_lock);
goto refind_writable;
}

Expand Down Expand Up @@ -4461,17 +4458,15 @@ static int cifs_readpage(struct file *file, struct page *page)
static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
{
struct cifsFileInfo *open_file;
struct cifs_tcon *tcon =
cifs_sb_master_tcon(CIFS_SB(cifs_inode->vfs_inode.i_sb));

spin_lock(&tcon->open_file_lock);
spin_lock(&cifs_inode->open_file_lock);
list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
spin_unlock(&tcon->open_file_lock);
spin_unlock(&cifs_inode->open_file_lock);
return 1;
}
}
spin_unlock(&tcon->open_file_lock);
spin_unlock(&cifs_inode->open_file_lock);
return 0;
}

Expand Down

0 comments on commit cb24881

Please sign in to comment.