diff --git a/debian/changelog b/debian/changelog index 77842f051..63bfc4111 100644 --- a/debian/changelog +++ b/debian/changelog @@ -1,8 +1,13 @@ linux (4.4.2-4) UNRELEASED; urgency=medium + [ Roger Shimizu ] * [armhf] dts: imx6dlq-wandboard-revb1: use unique model id (Closes: #813881). + [ Ben Hutchings ] + * unix: correctly track in-flight fds in sending process user_struct + (regression in 4.3.3-6) + -- Roger Shimizu Wed, 24 Feb 2016 01:30:38 +0900 linux (4.4.2-3) unstable; urgency=medium diff --git a/debian/config/defines b/debian/config/defines index 809d82b13..bad6b6548 100644 --- a/debian/config/defines +++ b/debian/config/defines @@ -1,5 +1,11 @@ [abi] abiname: 1 +ignore-changes: +# Not used by OOT modules + __scm_destroy + __scm_send + scm_detach_fds + scm_fp_dup [base] arches: diff --git a/debian/patches/bugfix/all/unix-correctly-track-in-flight-fds-in-sending-process-user_struct.patch b/debian/patches/bugfix/all/unix-correctly-track-in-flight-fds-in-sending-process-user_struct.patch new file mode 100644 index 000000000..b646fcc36 --- /dev/null +++ b/debian/patches/bugfix/all/unix-correctly-track-in-flight-fds-in-sending-process-user_struct.patch @@ -0,0 +1,155 @@ +From: Hannes Frederic Sowa +Date: Wed, 3 Feb 2016 02:11:03 +0100 +Subject: unix: correctly track in-flight fds in sending process user_struct +Origin: https://git.kernel.org/linus/415e3d3e90ce9e18727e8843ae343eda5a58fad6 + +The commit referenced in the Fixes tag incorrectly accounted the number +of in-flight fds over a unix domain socket to the original opener +of the file-descriptor. This allows another process to arbitrary +deplete the original file-openers resource limit for the maximum of +open files. Instead the sending processes and its struct cred should +be credited. + +To do so, we add a reference counted struct user_struct pointer to the +scm_fp_list and use it to account for the number of inflight unix fds. + +Fixes: 712f4aad406bb1 ("unix: properly account for FDs passed over unix sockets") +Reported-by: David Herrmann +Cc: David Herrmann +Cc: Willy Tarreau +Cc: Linus Torvalds +Suggested-by: Linus Torvalds +Signed-off-by: Hannes Frederic Sowa +Signed-off-by: David S. Miller +--- + include/net/af_unix.h | 4 ++-- + include/net/scm.h | 1 + + net/core/scm.c | 7 +++++++ + net/unix/af_unix.c | 4 ++-- + net/unix/garbage.c | 8 ++++---- + 5 files changed, 16 insertions(+), 8 deletions(-) + +diff --git a/include/net/af_unix.h b/include/net/af_unix.h +index 2a91a0561a47..9b4c418bebd8 100644 +--- a/include/net/af_unix.h ++++ b/include/net/af_unix.h +@@ -6,8 +6,8 @@ + #include + #include + +-void unix_inflight(struct file *fp); +-void unix_notinflight(struct file *fp); ++void unix_inflight(struct user_struct *user, struct file *fp); ++void unix_notinflight(struct user_struct *user, struct file *fp); + void unix_gc(void); + void wait_for_unix_gc(void); + struct sock *unix_get_socket(struct file *filp); +diff --git a/include/net/scm.h b/include/net/scm.h +index 262532d111f5..59fa93c01d2a 100644 +--- a/include/net/scm.h ++++ b/include/net/scm.h +@@ -21,6 +21,7 @@ struct scm_creds { + struct scm_fp_list { + short count; + short max; ++ struct user_struct *user; + struct file *fp[SCM_MAX_FD]; + }; + +diff --git a/net/core/scm.c b/net/core/scm.c +index 14596fb37172..2696aefdc148 100644 +--- a/net/core/scm.c ++++ b/net/core/scm.c +@@ -87,6 +87,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp) + *fplp = fpl; + fpl->count = 0; + fpl->max = SCM_MAX_FD; ++ fpl->user = NULL; + } + fpp = &fpl->fp[fpl->count]; + +@@ -107,6 +108,10 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp) + *fpp++ = file; + fpl->count++; + } ++ ++ if (!fpl->user) ++ fpl->user = get_uid(current_user()); ++ + return num; + } + +@@ -119,6 +124,7 @@ void __scm_destroy(struct scm_cookie *scm) + scm->fp = NULL; + for (i=fpl->count-1; i>=0; i--) + fput(fpl->fp[i]); ++ free_uid(fpl->user); + kfree(fpl); + } + } +@@ -336,6 +342,7 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl) + for (i = 0; i < fpl->count; i++) + get_file(fpl->fp[i]); + new_fpl->max = new_fpl->count; ++ new_fpl->user = get_uid(fpl->user); + } + return new_fpl; + } +diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c +index 49d5093eb055..29be035f9c65 100644 +--- a/net/unix/af_unix.c ++++ b/net/unix/af_unix.c +@@ -1496,7 +1496,7 @@ static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb) + UNIXCB(skb).fp = NULL; + + for (i = scm->fp->count-1; i >= 0; i--) +- unix_notinflight(scm->fp->fp[i]); ++ unix_notinflight(scm->fp->user, scm->fp->fp[i]); + } + + static void unix_destruct_scm(struct sk_buff *skb) +@@ -1561,7 +1561,7 @@ static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb) + return -ENOMEM; + + for (i = scm->fp->count - 1; i >= 0; i--) +- unix_inflight(scm->fp->fp[i]); ++ unix_inflight(scm->fp->user, scm->fp->fp[i]); + return max_level; + } + +diff --git a/net/unix/garbage.c b/net/unix/garbage.c +index 8fcdc2283af5..6a0d48525fcf 100644 +--- a/net/unix/garbage.c ++++ b/net/unix/garbage.c +@@ -116,7 +116,7 @@ struct sock *unix_get_socket(struct file *filp) + * descriptor if it is for an AF_UNIX socket. + */ + +-void unix_inflight(struct file *fp) ++void unix_inflight(struct user_struct *user, struct file *fp) + { + struct sock *s = unix_get_socket(fp); + +@@ -133,11 +133,11 @@ void unix_inflight(struct file *fp) + } + unix_tot_inflight++; + } +- fp->f_cred->user->unix_inflight++; ++ user->unix_inflight++; + spin_unlock(&unix_gc_lock); + } + +-void unix_notinflight(struct file *fp) ++void unix_notinflight(struct user_struct *user, struct file *fp) + { + struct sock *s = unix_get_socket(fp); + +@@ -152,7 +152,7 @@ void unix_notinflight(struct file *fp) + list_del_init(&u->link); + unix_tot_inflight--; + } +- fp->f_cred->user->unix_inflight--; ++ user->unix_inflight--; + spin_unlock(&unix_gc_lock); + } + diff --git a/debian/patches/series b/debian/patches/series index 38b5e82c8..6a7a98293 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -133,3 +133,4 @@ bugfix/all/iff_no_queue-fix-for-drivers-not-calling-ether_setup.patch bugfix/arm/net-mv643xx_eth-fix-packet-corruption-with-tso-and-t.patch bugfix/x86/x86-efi-bgrt-fix-kernel-panic-when-mapping-bgrt-data.patch bugfix/x86/x86-efi-bgrt-replace-early_memremap-with-memremap.patch +bugfix/all/unix-correctly-track-in-flight-fds-in-sending-process-user_struct.patch