diff options
author | Andreas Eversberg <jolly@eversberg.eu> | 2024-02-15 12:14:48 +0100 |
---|---|---|
committer | Andreas Eversberg <jolly@eversberg.eu> | 2024-02-29 09:15:38 +0100 |
commit | 0f123aa6fc8f8bab127ba08a5d026a7f349ef607 (patch) | |
tree | 6e07ff1f6c180ed7b1696a5148c8f35cb2379e06 /src/core/osmo_io_uring.c | |
parent | 8db6009a3a85501760d1dfa9285dde6112b0d83f (diff) |
osmo_io_uring: Detach msghdr from iofd before calling iofd_handle_send_completion()
msghdr must be detached, because subsequent callback at
iofd_handle_send_completion() may destroy the iofd (which in turn
frees this msghdr, if still attached) and frees the msghdr, causing a
double free.
Related: OS#5751
Change-Id: Ia349f73de2145fa360b20dd40deb73a8ffc71f07
Diffstat (limited to 'src/core/osmo_io_uring.c')
-rw-r--r-- | src/core/osmo_io_uring.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/src/core/osmo_io_uring.c b/src/core/osmo_io_uring.c index 3812b50b..cb636da1 100644 --- a/src/core/osmo_io_uring.c +++ b/src/core/osmo_io_uring.c @@ -195,6 +195,15 @@ static void iofd_uring_handle_tx(struct iofd_msghdr *msghdr, int rc) { struct osmo_io_fd *iofd = msghdr->iofd; + /* Detach msghdr from iofd. It might get freed here or it is freed during iofd_handle_send_completion(). + * If there is pending data to send, iofd_uring_submit_tx() will attach it again. + * iofd_handle_send_completion() will invoke a callback function to signal the possibility of write/send. + * This callback function might close iofd, leading to the potential freeing of iofd->u.uring.write_msghdr if + * still attached. Since iofd_handle_send_completion() frees msghdr at the end of the function, detaching + * msghdr here prevents a double-free bug. */ + if (iofd->u.uring.write_msghdr == msghdr) + iofd->u.uring.write_msghdr = NULL; + if (OSMO_UNLIKELY(IOFD_FLAG_ISSET(iofd, IOFD_FLAG_CLOSED))) { msgb_free(msghdr->msg); iofd_msghdr_free(msghdr); @@ -202,7 +211,6 @@ static void iofd_uring_handle_tx(struct iofd_msghdr *msghdr, int rc) iofd_handle_send_completion(iofd, rc, msghdr); } - iofd->u.uring.write_msghdr = NULL; /* submit the next to-be-transmitted message for this file descriptor */ if (iofd->u.uring.write_enabled && !IOFD_FLAG_ISSET(iofd, IOFD_FLAG_CLOSED)) iofd_uring_submit_tx(iofd); |